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mathematics
|
How many seconds will a 500 m long train take to cross a man walking with a speed of 3 km/hr in the direction of the moving train if the speed of the train is 63 km/hr?
|
[
"20 sec",
"10 sec",
"5 sec",
"30 sec",
"60 sec"
] |
Explanation:
Speed of train relative to man = 63 - 3 = 60 km/hr.
= 60 * 5/18 = 50/3 m/sec.
Time taken to pass the man = 500 * 3/50 = 30 sec.
Answer:D
The answer is: D
|
D
|
mathematics
|
During a behavioral experiment in a psychology class, each student is asked to compute his or her lucky number by raising 7 to the power of the student's favorite day of the week (numbered 1 through 7 for Monday through Sunday respectively), multiplying the result by 3, and adding this to the doubled age of the student in years, rounded to the nearest year. If a class consists of 28 students, what is the probability that the median lucky number in the class will be a non-integer?
|
[
"0%",
"10%",
"20%",
"30%",
"40%"
] |
Student's age is integral value. In question, we are multiplying student's age by 2 and adding some 3* 7^x something over there.
It means Even (2* age of students) + Odd (3) * 7 ^x (where x is day of week).
We know that 7^x is always odd. (e.g. 7, 49, 243, 1701, and repeat).
=> 3* odd is again odd.
2 * age of students is always even.
So final equation is even +odd = odd.
Avg of any number of odd digits or any number of even digits can never be non integral value. So 0% is the answer A.
The answer is: A
|
A
|
mathematics
|
Raman mixed 44 kg of butter at Rs. 150 per kg with 36 kg butter at the rate of Rs. 125 per kg. At what price per kg should he sell the mixture to make a profit of 40% in the transaction?
|
[
"129.25",
"287.25",
"194.25",
"188.25",
"112.25"
] |
Explanation:
CP per kg of mixture = [44(150) + 36(125)]/(44 + 36) = Rs. 138.75
SP = CP[(100 + profit%)/100]
= 138.75 * [(100 + 40)/100] = Rs. 194.25
Answer:C
The answer is: C
|
C
|
mathematics
|
There are different 20 circles. What is the number of the greatest possible points with which the circles intersect?
|
[
"380",
"200",
"110",
"180",
"200"
] |
Maximum points of intersection between n different circles = n*(n - 1) = 20*19 = 380
Answer: A
The answer is: A
|
A
|
mathematics
|
In a certain store, the profit is 320% of the cost. If the cost increases by 25% but the selling price remains constant, approximately what percentage of the selling price is the profit?
|
[
"30%",
"70%",
"100%",
"250%",
"none"
] |
Let C.P.= Rs. 100. Then, Profit = Rs. 320, S.P. = Rs. 420.
New C.P. = 125% of Rs. 100 = Rs. 125
New S.P. = Rs. 420.
Profit = Rs. (420 - 125) = Rs. 295
Required percentage = (295/420 * 100)% = 1475/21 % = 70% (approximately)
Answer = B
The answer is: B
|
B
|
mathematics
|
A and B walk around a circular track. They start at 9 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?
|
[
"8",
"7",
"6",
"5",
"3"
] |
Sol.
Relative speed = (2 + 3) = 5 rounds per hour.
So, they cross each other 5 times in an hour and 2 times in half an hour.
Hence, they cross each other 7 times before 9.30 a.m.
Answer B
The answer is: B
|
B
|
mathematics
|
How many four digit numbers have no repeat digits, do not contain zero, and have a sum of digits D equal to 28?
|
[
"14",
"24",
"28",
"48",
"96"
] |
First, look for all 4 digits without repeat that add up to 28. To avoid repetition, start with the highest numbers first.
Start from the largest number possible 9874.
Then the next largest number possible is 9865.
After this, you'll realize no other solution. Clearly the solution needs to start with a 9 (cuz otherwise 8765 is the largest possible, but only equals 26). With a 9, you also need an 8 (cuz otherwise 9765 is the largest possible, but only equals 27). With 98__ only 74 and 65 work.
So you have two solutions. Each can be rearranged in 4!=24 ways. So D=24+24=48.D
The answer is: D
|
D
|
mathematics
|
A 3-digit number 4a3 is added to another 3-digit number 984 to give a 4-digit number 13b7, which is divisible by 11. Then, (a + b) = ?
|
[
"10",
"11",
"12",
"15",
"17"
] |
Explanation:
4 a 3 |
9 8 4 } ==> a + 8 = b ==> b - a = 8
13 b 7 |
Also, 13 b7 is divisible by 11 (7 + 3) - (b + 1) = (9 - b)
(9 - b) = 0
b = 9
(b = 9 and a = 1) (a + b) = 10.
Answer: Option A
The answer is: A
|
A
|
mathematics
|
In a group of 100 people, 90 have an age of more 30 years, and the others have an age of less than 20 years. If a person is selected at random from this group, what is the probability the person's age is less than 20?
|
[
"0.1",
"0.55",
"0.65",
"0.75",
"0.85"
] |
Number of people whose age is less than 20 is given by
100 - 90 = 10
Probability P that a person selected at random from the group is less than 20 is given by
10 / 100 = 0.1
correct answer A
The answer is: A
|
A
|
mathematics
|
Average monthly income of a family of 4 earning members was Rs. 782. One of the earning members died and therefore, the average income came down to Rs 650. The income of the deceased was?
|
[
"Rs. 1178",
"Rs. 820",
"Rs. 990",
"Rs. 1385",
"None"
] |
Answer
Income of the deceased = Total income of 4 members - total income of remaining 3 members.
= 782 x 4 - 650 x 3 Rs.
= 1178 Rs.
Correct Option: A
The answer is: A
|
A
|
mathematics
|
What is the product between the place values of two 8's in the numeral 780.38
|
[
"0.16",
"0.64",
"80.08",
"64",
"6.4"
] |
Required product = 80 x 0.08 = 6.4
Answer is E
The answer is: E
|
E
|
mathematics
|
A jogger running at 9 km/hr along side a railway track is 240 m ahead of the engine of a 120 m long train running at 45 km/hr in the same direction. In how much time will the train pass the jogger?
|
[
"35",
"34",
"36",
"32",
"31"
] |
Speed of train relative to jogger = 45 - 9 = 36 km/hr.
= 36 * 5/18 = 10 m/sec.
Distance to be covered = 240 + 120 = 360 m.
Time taken = 360/10 = 36 sec.
Answer: C
The answer is: C
|
C
|
mathematics
|
Two employees X and Y are paid a total of Rs. 580 per week by their employer. If X is paid 120 percent of the sum paid to Y, how much is Y paid per week?
|
[
"s.263",
"s.283",
"s.293",
"s.300",
"s.383"
] |
Let the amount paid to X per week = x
and the amount paid to Y per week = y
Then x + y = 580
But x = 120% of y = 120y/100 = 12y/10
∴12y/10 + y = 580
⇒ y[12/10 + 1] = 580
⇒ 22y/10 = 580
⇒ 22y = 5800
⇒ y = 5800/22 = Rs.263
A)
The answer is: A
|
A
|
mathematics
|
There r 4 prime numbers in ascending order. The multiplication of first 3 is 385 and that of last 3is 1001. what is the last number is
|
[
"10",
"11",
"12",
"13",
"15"
] |
Explanation:
abcbcd=3851001=>ad=513
abcbcd=3851001=>ad=513
So d = 13
D
The answer is: D
|
D
|
mathematics
|
In how many ways can the letters D, I, S, I, N, O, I, C be arranged so that the three I's are not next to each other?
|
[
"36",
"48",
"72",
"96",
"6000"
] |
1 D
3 I
1 S
1 N
1 O
1 C
Number of ways these letters can be arranged = 8!/3! (3! to account 3 same Is) = 6720
Consider 3 Is as 1 entity and thus the number of arrangements for (III)DSNOC = 6! = 720
Total allowed cases = 6720-720 =6000
E is the correct answer.
The answer is: E
|
E
|
mathematics
|
From a group of 5men and 4 women, 3 persons are to be selected to form a committee so that at least 2 men are there are on the committee. In how many ways can it be done?
|
[
"20",
"50",
"65",
"86",
"96"
] |
We have (2men and 1 woman) or (3men only)
Therefore, Required number of ways= (5C2*4C1) + (5C3)
= (5*4)/(2*1) * 4 + 5C2
= 10*4 + 10
= 40 +10
=50
ANSWER:B
The answer is: B
|
B
|
mathematics
|
15 men take 21 days of 8 hrs. each to do a piece of work. How many days of 2 hrs. each would it take for 21 women if 3 women do as much work as 2 men?
|
[
"30",
"20",
"40",
"60",
"90"
] |
Let 1Man does 1unit/hr of work
15M in 21 days of 8hrs will do (15*21*8) units
3W = 2M
1W=(2/3)units/hr
21W with 2hrs a day will take (15*21*8)/(21*2*(2/3)) days
=> 90 Days
ANSWER:E
The answer is: E
|
E
|
mathematics
|
Over a three-week period, the price of an ounce of gold increased by 10% in the first week, decreased by 20% in the following week, and increased by 30% in the third week. If the price of gold was G dollars per ounce at the beginning of the three weeks, what was the price at the end of the three weeks?
|
[
"1.124G",
"1.144G",
"1.164G",
"1.184G",
"1.204G"
] |
After 3 weeks, the price was 1.3*0.8*1.1*G=1.144G
The answer is B.
The answer is: B
|
B
|
mathematics
|
Eight participants are participating in a competition. In how many ways can the first three prizes be won?
|
[
"920",
"680",
"820",
"336",
"620"
] |
Out of 8 participants, the first three prizes can be won in,
8P3 = 8! / (8 - 3)!
= 8 x 7 x 6
= 336 ways
ANSWER:D
The answer is: D
|
D
|
mathematics
|
What sum of money will produce Rs.70 as simple interest in 4 years at 3 1/2 percent?
|
[
"Rs.525",
"Rs.500",
"Rs.550",
"Rs.555",
"Rs.545"
] |
70 = (P*4*7/2)/100
P = 500
Answer:B
The answer is: B
|
B
|
mathematics
|
In a railway compartment, there are 2 rows of seats facing each other with accommodation for 5 in each, 4 wish to sit facing forward and 3 facing towards the rear while 3 others are indifferent. In how many ways can the 10 passengers be seated?
|
[
"172000",
"12600",
"45920",
"43200",
"None"
] |
Solution:
The four person who wish to sit facing forward can be seated in: 5P4 ways and 3 who wish to sit facing towards the rear can be seated in: 5P3 ways and the remaining 3 can be seated in the remaining 3 seats in 3P3 ways. Total number of ways =5P4 *5P3 *3P3 = 43200.
Answer: Option D
The answer is: D
|
D
|
mathematics
|
A 150 m long train crosses a platform in 39 sec while it crosses a signal pole in 18 sec. What is the length of the platform?
|
[
"300",
"175",
"360",
"370",
"380"
] |
Speed = 150/18 = 25/3 m/sec.
Let the length of the platform be x meters.
Then, (x + 150)/39 = 25/3
=> x = 325 m.
L=325-150 =175 m
Answer: Option B
The answer is: B
|
B
|
mathematics
|
C and D started a business by investing Rs.1000/- and Rs.1500/- respectively. Find the D’s share out of a total profit of Rs.500:
|
[
"400",
"300",
"200",
"100",
"150"
] |
C = Rs.1000/-
D = Rs.1500/-
C share 2 parts & D share 3 parts
Total 5 parts -----> Rs.500/-
----> 1 part -------> Rs.100/-
D share = 3 parts -----> Rs.300/-
D
The answer is: D
|
D
|
mathematics
|
Today Roseline, who is 50 years old, and her daughter, who is 20 years old, celebrate their birthdays. How many years will pass before Roseline’s age is twice her daughter’s age?
|
[
"12",
"13",
"10",
"15",
"18"
] |
Forget conventional ways of solving math questions. In PS, IVY approach is the easiest and quickest way to find the answer.
After x years passes Roseline’s age will be (50+x) years old, and her daughter’s age will be (20+x) years old. Since the Roseline’s age is twice her daughter’s age (50+x)= 2 * (20+x) ---> 50+x=40+2x ---> x= 10
The answer is (C).
The answer is: C
|
C
|
mathematics
|
A certain manufacturer of cake, muffin, and bread mixes has 100 buyers, of whom 50 purchases cake mix, 40 purchase muffin mix, and 16 purchase both cake mix and muffin mix. If a buyer is to be selected at random from the 100 buyers, what is the probability that the buyer selected will be one who purchases neither cake mix nor muffin mix?
|
[
"1/10",
"13/50",
"1/2",
"7/10",
"9/10"
] |
C+M+B-CM-MB-CB-2CMB = 100
C - cake buyers, M - muffin and B - Bread buyers. CM,MB,CB and CMB are intersecting regions.
the question asks for people who have bought only bread mixes = B-CB-MB-2CMB has to be found out.
50 + 40 + B-CB-MB-16-2CMB = 100
B-CB-MB-2CMB =26
hence the probability = 26/100 = 13/50.
B
The answer is: B
|
B
|
mathematics
|
The greatest common factor of positive integers m and n is 15. What is the greatest common factor of (2m^2, 2n^2)?
|
[
"15",
"30",
"150",
"450",
"900"
] |
m = 15j and n = 15k, where the greatest common factor of j and k is 1.
2m^2 = 2*15*15*j^2 and 2n^2 = 2*15*15*k^2
The greatest common factor of 2m^2 and 2n^2 is 2*15*15 = 450
The answer is D.
The answer is: D
|
D
|
mathematics
|
In a school 50% of the students are younger than 10, 1/20 are 10 years old and 1/10 are older than 10 but younger than 12, the remaining 70 students are 12 years or older. How many students are 10 years old?
|
[
"5",
"6",
"7",
"8",
"10"
] |
Let us write the fraction for each group of students
Group A: younger than 10: 50% = 50/100 = 1/2
Group B: 10 years old: 1/20
Group C: older that 10 but younger than 12: 1/10
Group D: 12 years or older: 70 students
The fraction for group A, B and C together is given by
1 / 2 + 1 / 20 + 1 / 10 = 10 / 20 + 1 / 20 + 2 / 20 , common denominator
= 13 / 20 , add numerators
The fraction for group D is given by
20 / 20 - 13 / 20 = 7 / 20 and corresponds to 70 students
If X is the total number of students, then
7 / 20 of X = 70
or (7 / 20) × X = 70
Solve for X
X = 70 × (20 / 7) = 200
Students who are 10 years old have a fraction of 1 / 20 of the total X and their number is equal to
(1 / 20) of 200 = 10 students
correct answer is E)10
The answer is: E
|
E
|
mathematics
|
If you are given $3, and the amount doubles every day, how much money will you have after 9 days?
|
[
"$19683",
"$19898",
"$10242",
"$20481",
"$14096"
] |
3^9=19683
The answer is A
The answer is: A
|
A
|
mathematics
|
In a division sum, the remainder is 6 and the divisor is 5 times the quotient and is obtained by adding 2 to the thrice of the remainder. The dividend is?
|
[
"75",
"78",
"80",
"82",
"86"
] |
Divisor = (6 * 3) + 2 = 20
5 * Quotient = 20
Quotient = 4.
Dividend = (Divisor * Quotient) + Remainder
Dividend = (20 * 4) + 6 = 86
E)
The answer is: E
|
E
|
mathematics
|
By selling 150 mangoes, a fruit-seller gains the selling price of 30 mangoes. Find the gain percent?
|
[
"22",
"25",
"77",
"88",
"99"
] |
SP = CP + g
150 SP = 150 CP + 30 SP
120 SP = 150 CP
120 --- 30 CP
100 --- ? => 25%
Answer:B
The answer is: B
|
B
|
mathematics
|
In the construction of a house, some persons can do a piece of work in 8 days. Four times the number of such persons will do half of that work in :
|
[
"1 day",
"2 days",
"3 days",
"4 days",
"None of these"
] |
Explanation :
Solution: Let x men can do the work in 8 days and the required number of days be z.
More men, less days (IP)
Less work, less days (DP)
men 4x : x
} : : 8 : z
Work 1 : 1/2
.'. (4x*1*z) = (x*1/2 * 8)
=> z = 1
Answer : A
The answer is: A
|
A
|
mathematics
|
Four car rental agencies A, B, C and D rented a plot for parking their cars during the night. A parked 15 cars for 12 days, B parked 12 cars for 20 days, C parked 18 cars for 18 days and D parked 16 cars for 15 days. If A paid Rs. 1125 as rent for parking his cars, what is the total rent paid by all the four agencies?
|
[
"6157",
"6187",
"6128",
"6150",
"6113"
] |
The ratio in which the four agencies will be paying the rents = 15 * 12 : 12 * 20 : 18 * 18 : 16 * 15
= 180 : 240 : 324 : 240 = 45 : 60 : 81 : 60
Let us consider the four amounts to be 45k, 60k, 81k and 60k respectively.
The total rent paid by the four agencies = 45k + 60k + 81k + 60k= 246k
It is given that A paid Rs. 1125
45k = 1125 => k = 25
246k = 246(25) = Rs. 6150
Thus the total rent paid by all the four agencies is Rs. 6150.
Answer: D
The answer is: D
|
D
|
mathematics
|
If n is a negative integer and p is a positive integer, which of the options below must be positive?
|
[
"(n + p)^2",
"np",
"n/p",
"p/n",
"none of the above"
] |
A.(n + p)^2
will be positive irrespective of the absolute values of x and y
will be positive always
B. np
-ve*+ve=-ve
will be negative
C. n/p
-ve*/ve=-ve
D.+ve/-ve=-ve
+ve/-ve=-ve
Answer A
The answer is: A
|
A
|
mathematics
|
A type of extra-large SUV averages 12.2 miles per gallon (mpg) on the highway, but only 7.6 mpg in the city. What is the maximum distance, in miles, that this SUV could be driven on 21 gallons of gasoline?
|
[
"190",
"284.6",
"300",
"256",
"312"
] |
so 12.2 * 21 = 256..
IMO option D is correct answer..
The answer is: D
|
D
|
mathematics
|
If the price of an article went up by 20%, then by what percent should it be brought down to bring it back to its original price?
|
[
"16 2/3%",
"16 2/6%",
"16 8/3%",
"17 2/3%",
"16 2/1%"
] |
Let the price of the article be Rs. 100.
20% of 100 = 20.
New price = 100 + 20 = Rs. 120
Required percentage = (120 - 100)/120 * 100
= 20/120 * 100 = 50/3 = 16 2/3%.
Answer:A
The answer is: A
|
A
|
mathematics
|
When Jessica withdrew $200 from her bank account, her account balance decreased by 2/5. If she deposits an amount equal to 1/5 of the remaining balance, what will be the final balance in her bank account?
|
[
"300",
"360",
"400",
"500",
"575"
] |
As per the question 200=2a/5
thus- a which is the total amount =500
The amount thus left =300
She then deposited 1/5 of 300=60
total amount in her account =360
Answer B
The answer is: B
|
B
|
mathematics
|
A sum of money at simple interest amounts to Rs. 825 in 3 years and to Rs. 840 in 4 years. The sum is?
|
[
"s. 738",
"s. 638",
"s. 777",
"s. 730",
"s. 735"
] |
S.I. for 1 year = (841 - 825) = Rs. 16
S.I. for 3 years = 16 * 3 = Rs. 48
Principal = (825 - 48) = Rs. 777.
ANSWER:C
The answer is: C
|
C
|
mathematics
|
What no. should be subtracted from x^3+4x^2−7x+12x^3+4x^2−7x+12, if it is to be perfectly divisible by x+3x+3?
|
[
"34",
"42",
"48",
"49",
"53"
] |
According to remainder theorem when dfracf(x)x+adfracf(x)x+a, then the remainder is f(−a)f(−a).
In this case, as x+3x+3 divides x3+4x2−7x+12–kx3+4x2−7x+12–k perfectly (kk being the number to be subtracted), the remainder is 0 when the value of xx is substituted by -3.
i.e., (−3)3+4(−3)2−7(−3)+12−k=0(−3)3+4(−3)2−7(−3)+12−k=0
or −27+36+21+12=k−27+36+21+12=k
or k=k= 42
B
The answer is: B
|
B
|
mathematics
|
On a partly rainy day, Derek decides to walk back from work. When it is sunny, he walks at a speed of s miles/hr (s is an integer) and when it gets cloudy, he increases his speed to (s + 1) miles/hr. If his average speed for the entire distance is 2.8 miles/hr, what fraction of the total distance did he cover while the sun was shining on him?
|
[
"1/7",
"1/4",
"1/3",
"1/2",
"1"
] |
If s is an integer and we know that the average speed is 2.8, s must be = 2. That meanss+1= 3. This implies that the ratio of time for s=2 is 1/4 of the total time. The formula for distance/rate is D=Rt...so the distance travelled when s=2 is 2t. The distance travelled for s+1=3 is 3*4t or 12t. Therefore, total distance covered while the sun was shining over him is 2/14 = 1/7. Answer: A
The answer is: A
|
A
|
mathematics
|
In a kilometer race, A beats B by 20 meters or 10 seconds. What time does A take to complete the race?
|
[
"490 sec",
"190 sec",
"176 sec",
"716 sec",
"123 sec"
] |
Time taken by B run 1000 meters
= (1000 * 10)/20 = 500 sec.
Time taken by A = 500 - 10
= 490 sec.
Answer:A
The answer is: A
|
A
|
mathematics
|
The difference of two numbers is 1365. on dividing the larger number by the smaller, we get 6 as quotient and 15 as remainder. What is the smaller number?
|
[
"240",
"270",
"295",
"360",
"None of these"
] |
Let the smaller number be x. Then larger number = (x+1365).
x+1365=6x+15, 5x=1350, x=270
Smaller number=270.
Correct Option: B
The answer is: B
|
B
|
mathematics
|
At a party, everyone shook hands with everybody else. There were 66 handshakes. How many people were at the party?
|
[
"12",
"11",
"10",
"9",
"5"
] |
A
12
In general, with n+1 people, the number of handshakes is the sum of the first n consecutive numbers: 1+2+3+ ... + n.
Since this sum is n(n+1)/2, we need to solve the equation n(n+1)/2 = 66.
This is the quadratic equation n2+ n -132 = 0. Solving for n, we obtain 11 as the answer and deduce that there were 12 people at the party.
Since 66 is a relatively small number, you can also solve this problem with a hand calculator. Add 1 + 2 = + 3 = +... etc. until the total is 66. The last number that you entered (11) is n.
The answer is: A
|
A
|
mathematics
|
If a and b are integers and (a*b)^5 = 64y, y could be:
|
[
"16",
"32",
"64",
"128",
"256"
] |
Distribute the exponent.
a^5 * b^5 = 64 y
Find the prime factorization of 64. This is 2^5 *2^1
We need 2^4 (or some other power of 2 that will give us a multiple of 2^5 as our second term).
2^4 = 16
The answer is A.
The answer is: A
|
A
|
mathematics
|
What is the remainder when 7^498 is divided by 5 ?
|
[
"4",
"3",
"2",
"1",
"0"
] |
7^0 = 1
7^1 = 7
7^2 = 49
7^3 = 343
7^4 = ...1
7^5 = ....7
7^6 = ......9
and so on in a recurring pattern of 1,7,9,3,1,7,9,3....
498/4 = 124 (with a remainder 2) so the last number is a 9.
so when 7^498 is divided by 5 the remainder is 4, ANS = A
The answer is: A
|
A
|
mathematics
|
First bunch of bananas has (1/4) again as many bananas as a second bunch. If the second bunch has 3 bananas less than the first bunch, then the number of bananas in the first bunch is
|
[
"9",
"10",
"12",
"15",
"17"
] |
x is the no.of banana's in second bunch
first bunh banan's will be x+(1/4)x= x*5/4
If the second bunch has 3 bananas less than the first bunch
X*5/4 = x+3, X=12,
First bunch bannana's will be 15
ANSWER:D
The answer is: D
|
D
|
mathematics
|
If A can finish a work in 12 days and B can finish same work in 15 days.then they together can finish that work in how many days?
|
[
"15",
"12",
"20/3",
"8",
"10/3"
] |
A work in 1 hour=1/12,B work in 1 hour=1/15
[A+B] work in 1 hour=[1/12+1/15] = 3/20
Time take by both to finish the work=20/3hour
Answer C
The answer is: C
|
C
|
mathematics
|
In a group of ducks and cows, the total number of legs are 30 more than twice the no. of heads. Find the total no.of buffaloes.
|
[
"11",
"12",
"14",
"15",
"18"
] |
Let the number of buffaloes be x and the number of ducks be y
=> 4x + 2y = 2 (x + y) + 30
=> 2x = 30 => x = 15
D
The answer is: D
|
D
|
mathematics
|
How many paying stones, each measuring 2 1/2 m * 2 m are required to pave a rectangular court yard 30 m long and 16 1/2 m board?
|
[
"90",
"99",
"97",
"95",
"65"
] |
30 * 33/2 = 5/2 * 2 * x => x = 99
ANSWER B
The answer is: B
|
B
|
mathematics
|
On his first day working out, Anthony did
30 push-ups. On each successive day, he
did exactly 3 more push-ups than on the
previous day. After completing his push-ups
on the 30th day, how many push-ups had
he completed on all 30 days?
|
[
"fewer than 500",
"between 500 and 1,000",
"between 1,000 and 1,500",
"between 1,500 and 2,000",
"more than 2,000"
] |
Anthony completed 30 push-ups the first day, 33 the second day, 36 the third day, and
so on. Make a chart as follows:
1 2 3 4 5 . . . 10 . . . 15 . . . 20 . . . 25 . . . 30
30 33 36 39 42 57 72 87 102 117
To save time adding all these numbers, notice that the total of the first and 30th numbers
is 30 + 117 = 147. This total is the same for the 2nd and 29th, the 3rd and 28th, and so on all
the way to the 15th and 16th. Therefore, you have 15 pairings of days on which Anthony
completed 147 pushups. You can simply multiply to find the total: 147 × 15 = 2,205.
correct answer E) more than 2.000
The answer is: E
|
E
|
mathematics
|
The length of a room is 5.5 m and width is 3.75 m. Find the cost of paving the floor by slabs at the rate of Rs. 1000 per sq. metre.
|
[
"Rs. 15000",
"Rs. 15550",
"Rs. 15600",
"Rs. 20625",
"None of these"
] |
Solution
Area of the floor = (5.5 × 3.75) m2 = 20.625 m2
∴ Cost of paving = Rs. (1000 × 20.625) = 20625. Answer D
The answer is: D
|
D
|
mathematics
|
At Company K, 15 percent of the employees are secretaries and 60 percent are salespeople. If there are 60 other employees of Company K, how many employees does Company K have?
|
[
"240",
"180",
"190",
"200",
"400"
] |
Let the total number of employees in the company be x
% of secretaries = 15%
% of salespeople = 60%
% of of employees other than secretaries and salespeople = 100 - 75 = 25%
But this number is given as 60
so 25% of x = 60
x = 240
Therefore there a total of 240 employees in the company K
Correct answer - A
The answer is: A
|
A
|
mathematics
|
A car runs at the speed of 60 km per hour when not serviced and runs at 80 kmph when serviced. After servicing the car covers a certain distance in 4 hours. How much time will the car take to cover the same distance when not serviced?
|
[
"6 hours 12 minutes",
"5 hours 33 minutes",
"8 hours 15 minutes",
"7 hours 12 minutes",
"None"
] |
Explanation :
Time = 80*4 / 60 = 5 hours 33 mins
Answer – B
The answer is: B
|
B
|
mathematics
|
If a population of women in a town is 70% of men . What is the population of men as a % of population of women ?
|
[
"A)200%",
"B)144%",
"C)50%",
"D)65%",
"E)110%"
] |
We're told that the number of Women in a town is equal to 50% of the number of Men in that town.
IF....
Men = 10
Women = 7
We're asked for the number of Men, as a percentage of the number of Women.
M/W = 10/7 = 144%
Answer is B
The answer is: B
|
B
|
mathematics
|
What is the greatest number of three digits which is divisible by 10, 20, 30 ?
|
[
"960",
"970",
"980",
"990",
"965"
] |
Greatest number of 3 digits = 999
LCM of 10,20,30 = 60
999 ÷ 60= 16, remainder = 39
Hence, greatest number of four digits which is divisible by 10,20,30
= 999 - 39 = 960
answer : A
The answer is: A
|
A
|
mathematics
|
If r = (x – 5)^2 + (x + 1)^2 – 6, then y is least when x =
|
[
"-2",
"-1",
"0",
"2",
"None of the above"
] |
Let us transform the formula:
r = (x – 5)² + (x +1)² – 6 =
x² – 10x + 25 + x² + 2x + 1 – 6 =
2x² – 8x + 20 = 2 × (x² – 4x + 10) =
2 × ((x² – 4x + 4) + 6) =
2 × ((x – 2)² + 6)
Any square is greater or equal 0. Therefore the formula possess the least value when (x – 2)² = 0.
x – 2 = 0
x = 2
The correct answer is choice (D).
The answer is: D
|
D
|
mathematics
|
A, B and C enter into a partnership. A initially invests Rs. 25 lakhs and adds another Rs. 10 lakhs after one year. B initially invests Rs. 35 lakhs and withdraws Rs. 10 lakhs after 2 years and C invests Rs. 30 lakhs. In what ratio should the profits be divided at the end of 3 years ?
|
[
"11:10:15",
"20:17:23",
"19:19:18",
"5:4:9",
"None of these"
] |
Explanation:
A:B:CA:B:C =(25 lakhs××1)+(35 lakhs××2) :(35 lakhs××2+25 lakhs××1) :(30 lakhs××3)
= 95 lakhs : 95 lakhs : 90 lakhs =19:19:18=19:19:18.
ANSWER IS C
The answer is: C
|
C
|
mathematics
|
The length of the bridge, which a train 110 meters long and travelling at 45 km/hr can cross in 30 seconds, is:
|
[
"265",
"244",
"245",
"238",
"236"
] |
Speed = (45 * 5/18) m/sec = (25/2) m/sec. Time = 30 sec. Let the length of bridge be x meters. Then, (110 + X)/30 = 25/2 ==> 2(110 + X) = 750 ==> X = 265 m.
Answer: Option A
The answer is: A
|
A
|
mathematics
|
How many seconds will a 800 m long train take to cross a man walking with a speed of 3 km/hr in the direction of the moving train if the speed of the train is 63 km/hr?
|
[
"26 sec",
"32 sec",
"13 sec",
"48 sec",
"56 sec"
] |
Speed of train relative to man = 63 - 3 = 60 km/hr.
= 60 * 5/18 = 50/3 m/sec.
Time taken to pass the man = 800 * 3/50
= 48 sec.
Answer:D
The answer is: D
|
D
|
mathematics
|
What is the minimum percentage increase in the mean of set D {-4, -1, 0, 6, 9} if its two smallest elements are replaced with two different primes?
|
[
"25%",
"50%",
"75%",
"100%",
"200%"
] |
Mean of D is (-4-1+0+6+9)/5=2;
In order the increase to be minimal we should replace two smallest elements of D, which are -4 and -1, with two smallest primes, which are 2 and 3. Hence our new set will be {2, 3, 0, 6, 9} --> new mean is (2+3+0+6+9)/5=4.
Percent increase=(4-2)/2*100=100%.
Answer: D.
The answer is: D
|
D
|
mathematics
|
A fisherman has 18 fish, then he catches 3 more fish. Now how many fish does he have?
|
[
"A)21",
"B)15",
"C)17",
"D)23",
"E)4"
] |
18+3=21. Answer is A
The answer is: A
|
A
|
mathematics
|
The value of Underrot 72pi/9 + Underrot 4 is most nearly equal to which of the following integers? (Please refer to the picture below for the exact version of the question)
|
[
"27",
"14",
"18",
"19",
"21"
] |
Under root (72pi/9) ~ 25
Under root (4) = 2
Hence, 9+1 = 10 is the approx answer. A is the correct answer.
The answer is: A
|
A
|
mathematics
|
In a regular week, there are 5 working days and for each day, the working hours are 8. A man gets Rs. 2.50 per hour for regular work and Rs. 3.20 per hours for overtime. If he earns Rs. 432 in 4 weeks, then how many hours does he work for ?
|
[
"160",
"170",
"190",
"200",
"210"
] |
Suppose the man works overtime for x hours.
Now, working hours in 4 weeks = (5 x 8 x 4) = 160.
160 x 2.50 + X x 3.20 = 432
X = 10.
Hence, total hours of work = (160 + 10) = 170.
answer :B
The answer is: B
|
B
|
mathematics
|
When positive integer A is divided by positive integer B, the remainder is 5. If A/B = 58.25, what is the value of B?
|
[
"18",
"19",
"15",
"20",
"13"
] |
When positive integer A is divided by positive integer B, the remainder is 5 --> A=qB+5;
A/B=58.25 --> A=58B+0.25B (so q above equals to 58);
0.25B=6 --> B=20.
Answer: D.
The answer is: D
|
D
|
mathematics
|
?% of 360 = 115.2
|
[
"277",
"36",
"64",
"32",
"None of these"
] |
?% of 360 = 115.2
or, ? = 115.2×100/360=32
Answer D
The answer is: D
|
D
|
mathematics
|
There were two candidates in an election. Winner candidate received 62% of votes and won the election by 336 votes. Find the number of votes casted to the winning candidate?
|
[
"288",
"744",
"788",
"868",
"177"
] |
W = 62% L = 38%
62% - 38% = 24%
24% -------- 336
62% -------- ? => 868
Answer: D
The answer is: D
|
D
|
mathematics
|
Increasing the original price of a certain item by 25 percent and then increasing the new price by 25 percent is equivalent to increasing the original price by what percent?
|
[
"31.25",
"37.5",
"50.0",
"52.5",
"56.25"
] |
Soln:-
X*1.25*1.25 = 1.5625 X
so there is a net increase of 56.25% .
Answer E.
The answer is: E
|
E
|
mathematics
|
Of the families in City X in 1956, 25 percent owned a personal computer. The number of families in City X owning a computer in 1960 was 15 percent greater than it was in 1956, and the total number of families in City X was 5 percent greater in 1956 than it was in 1960. what percent of the families in City X owned a personal computer in 1960?
|
[
"50%",
"51.22%",
"5.26%",
"7.20%",
"27.38%"
] |
Say a 100 families existed in 1956 then the number of families owning a computer in 1956 - 25
Number of families owning computer in 1960 = 25 * 115/100 = 28.75
Number of families in 1960 = 105
The percentage = 28.75/105 * 100 = 27.38%.
Option: E
The answer is: E
|
E
|
mathematics
|
At a monthly meeting, 3/5 of the attendees were males and 4/5 of the male attendees arrived on time. If 5/6 of the female attendees arrived on time, what fraction of the attendees at the monthly meeting did not arrive on time?
|
[
"6/25",
"11/50",
"14/75",
"23/100",
"31/150"
] |
Males who did not arrive on time are 1/5*3/5 = 3/25 of the attendees.
Females who did not arrive on time are 1/6*2/5 = 1/15 of the attendees.
The fraction of all attendees who did not arrive on time is 3/25 + 1/15 = 14/75
The answer is C.
The answer is: C
|
C
|
mathematics
|
During a certain week, a seal ate 65% of the first 80 smelt it came across, and 30% of the remaining smelt it came across. If the seal ate 40% of the smelt it came across during the entire week, how many smelt did it eat?
|
[
"32",
"40",
"55",
"64",
"112"
] |
Total smelt = x.
Then, 0.65*80+0.3(x-80)=0.4*x --> x=280 --> 0.4*x=112.
Answer: E.
The answer is: E
|
E
|
mathematics
|
A train 110 m long is running with a speed of 60 km/hr. In what time will it pass a man who is running at 6 km/hr in the direction opposite to that in which the train is going?
|
[
"67 sec",
"6 sec",
"7 sec",
"5 sec",
"8.3 sec"
] |
Answer: Option B
Speed of train relative to man = 60 + 6 = 66 km/hr.
= 66 * 5/18 = 55/3 m/sec.
Time taken to pass the men = 110 * 3/55 = 6 sec.
The answer is: B
|
B
|
mathematics
|
The cost to rent a small bus for a trip is x dollars, which is to be shared equally among the people taking the trip. If 10 people take the trip rather than 15, how many more dollars, in terms of x, will it cost per person?
|
[
"x/6",
"x/16",
"x/40",
"3x/40",
"3x/80"
] |
Choose x as a multiple of 16, I chose 64:
So for 10 people, that's 6.4 each and for 16 people it's 4 USD each... Pick one of the options that gives you 6.4 - 4 = 2.4... The answer is D.
The answer is: D
|
D
|
mathematics
|
Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?
|
[
"887 gallons",
"176 gallons",
"120 gallons",
"289 gallons",
"976 gallons"
] |
Work done by the waste pipe in 1 minute
= 1/15 - (1/20 + 1/24) = - 1/40
Volume of 1/40 part
= 3 gallons
Volume of whole = 3 * 40
= 120 gallons.
Answer:C
The answer is: C
|
C
|
mathematics
|
A man can row with a speed of 10 kmph in still water. If the stream flows at 25 kmph, then the speed in downstream is?
|
[
"10 kmph",
"35 kmph",
"20 kmph",
"22 kmph",
"25 kmph"
] |
M = 10
S = 25
DS = 10 + 25 = 35
ANSWER:B
The answer is: B
|
B
|
mathematics
|
The security gate at a storage facility requires a five-digit lock code. If the lock code
must consist only of digits from 1 through 7, inclusive, with no repeated digits, and
the first and last digits of the code must be odd, how many lock codes are possible?
|
[
"120",
"240",
"360",
"720",
"1440"
] |
X-X-X-X-X --> there are 4 odd digits from 1 to 7, inclusive thus options for the first and the last X's are: 4-X-X-X-3. Other X's can take following values: 4-5-4-3-3 --> 4*5*4*3*3=720.
Answer: D.
The answer is: D
|
D
|
mathematics
|
A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?
|
[
"240",
"377",
"2908",
"287",
"201"
] |
Speed = (54 * 5/18) m/sec = 15 m/sec. Length of the train = (15 x 20)m = 300 m. Let the length of the platform be x meters. Then, (x + 300)/36 = 15 ==> x + 300 = 540 ==> x = 240 m.Answer: A
The answer is: A
|
A
|
mathematics
|
If KING is coded as 17 and MASS is coded as 29 Then DON is coded as
|
[
"12",
"16",
"18",
"None",
"cannot be determined"
] |
Explanation :
KING = 11+9+14+7=41 i.e (4*4)+(1*1)=17
MASS = 13+1+19+19=52 i.e (5*5)+(2*2)=29
DON = 4+14+15=33 i.e(3*3)+(3*3)=18
Hence (C) is correct
Answer : C
The answer is: C
|
C
|
mathematics
|
The largest 4 digit number exactly divisible by 88 is?
|
[
"A)9944",
"B)9954",
"C)9967",
"D)9969",
"E)9970"
] |
Largest 4-digit number = 9999
88) 9999 (113
88
----
119
88
----
319
264
---
55
---
Required number = (9999 - 55)
= 9944.
A)
The answer is: A
|
A
|
mathematics
|
John and Karen begin running at opposite ends of a trail until they meet somewhere in between their starting points. They each run at their respective constant rates until John gets a cramp and stops. If Karen runs 50% faster than John, who is only able to cover 25% of the distance w before he stops, what percent longer would Karen have run than she would have had John been able to maintain his constant rate until they met.
|
[
"25%",
"50%",
"75%",
"100%",
"200%"
] |
John and Karen begin running at opposite ends of a trail until they meet somewhere in between their starting points. They each run at their respective constant rates until John gets a cramp and stops. If Karen runs 50% faster than John, who is only able to cover 25% of the distance w before he stops, what percent longer would Karen have run than she would have had John been able to maintain his constant rate until they met.
Lets say the distance of the trail is 100 miles. Lets also say that J rate = 10 miles/hour and K rate = 15 miles/hour.
If John stops at the 25% mark that means he travels 25 miles in 2.5 hours. It would take Karen t=d/r t=75/15 = 5 hours to reach john. If John had not stopped, their combined rate would 10+15 = 25 miles/hour meaning they would have met in 4 hours. Therefore, she ran one hour longer (25%) longer than she would have needed to if John ran for the entire time.
ANSWER: A) 25%
The answer is: A
|
A
|
mathematics
|
How many 6 digit number can be formed from the digits 1, 2, 3, 4, 5, 6 which are divisible by 4 and digits are not repeated?
|
[
"192",
"122",
"140",
"242",
"None"
] |
Solution
For the number to be divisible by 4, the last two digits must be any of 12, 24, 16, 64, 32, 36, 56 and 52. The last two digit places can be filled in 8 ways. Remaining 3 places in 4P3 ways.
Hence no. of 5 digit nos. which are divisible by 4 are 24 × 8 = 192
Answer A
The answer is: A
|
A
|
mathematics
|
If x and y are positive numbers and z = xy^2, a 50 percent increase in x and a 20 percent decrease in y would result in which of the following changes in z?
|
[
"A decrease of 4%",
"A decrease of 14%",
"An increase of 4%",
"An increase of 20%",
"An increase of 30%"
] |
z= x*y^2
Now , since x increases by 50 % and y decreases by 20 %
z'=(3/2)x * (8/10)(8/10)y^2
= 192/200 * x*y^2
= 96/100 * x*y^2
= 96/100 * z
a decrease in 4 %
Answer A
The answer is: A
|
A
|
mathematics
|
How long does a train 110 m long running at the speed of 72 km/hr takes to cross a bridge 132 m length?
|
[
"12.6",
"12.0",
"12.1",
"12.3",
"12.2"
] |
Speed = 72 * 5/18 = 20 m/sec
Total distance covered = 110 + 132 = 242 m.
Required time = 242/20 = 12.1 sec.Answer: B
The answer is: B
|
B
|
mathematics
|
A man's regular pay is $3 per hour up to 40 hours. Overtime is twice the payment for regular time. If he was paid $186, how many hours overtime did he work?
|
[
"8",
"5",
"9",
"6",
"11"
] |
At $3 per hour up to 40 hours, regular pay = $3 x 40 = $120 If total pay = $168, overtime pay = $186 - $120 = $66 Overtime rate (twice regular) = 2 x $3 = $6 per hour => number of overtime hours = $66/$6 = 11
Ans is E
The answer is: E
|
E
|
mathematics
|
Suganya and Suriya are partners in a business. Suganya invests Rs. 35,000 for 8 months and Suriya invests Rs.42,000 for 10 months. Out of a profit of Rs.31,570. Suganya's share is
|
[
"Rs.9471",
"Rs.12,628",
"Rs.18,040",
"Rs.18,942",
"None"
] |
Solution
Ratio of their shares =(35000×8):(42000×10)
= 2 : 3.
Suganya's share = Rs.(31570 ×2/5)
= Rs.12628.
Answer C
The answer is: C
|
C
|
mathematics
|
A motorcyclist goes from Bombay to Nagpur, a distance of 600 kms at an average of 120 kmph speed. Another man starts from Bombay by car 1 ½ hours after the first, and reaches Nagpur ½ hour earlier. What is the ratio of the speed of the motorcycle and the car?
|
[
"1:2",
"1:7",
"1:9",
"3:5",
"1:1"
] |
T = 600/120 = 5 h
T = 5 - 2 = 3
Time Ratio = 5:3
Speed Ratio = 3:5
Answer: D
The answer is: D
|
D
|
mathematics
|
The radius of a semi circle is 6.3 cm then its perimeter is?
|
[
"12.9",
"32.4",
"32.1",
"32.2",
"32.7"
] |
36/7 r = 6.3
= 32.4
Answer: B
The answer is: B
|
B
|
mathematics
|
The sum and product of two numbers are 12 and 35 respectively. The sum of their reciprocals is
|
[
"12/35",
"1/35",
"35/8",
"35/9",
"1/45"
] |
X + Y = 12
XY = 35
1/X + 1/Y = (X + Y)/Xy = 12/35
Answer A.
The answer is: A
|
A
|
mathematics
|
After taking N tests, each containing 100 questions, John had an average of 70% of correct answers. How much does John need to score on the next test to make his average equal 70%?
M13-03.
|
[
"N−35",
"N+69",
"2N+70",
"2N+72",
"2N−35"
] |
Say N=1.
So, after 1 test John has 70 correct answers.
In 2 tests, so in 200 questions he needs to have 0.70*200=140 correct answers, so in the second test he must get 140-70=70 questions correctly.
Now, plug N=1 into the answer choices to see which one yields 70. Only option D fits.
Answer: B.
The answer is: B
|
B
|
mathematics
|
(7895632 x 881) = ?
|
[
"6846381250",
"6584638130",
"6584638135",
"6584638140",
"6956051792"
] |
7895632 x 881
=6956051792
Ans E
The answer is: E
|
E
|
mathematics
|
Two pipes can fill a tank in 20 minutes and 12 minutes. An outlet pipe can empty the tank in 10 minutes. If all the pipes are opened when the tank is empty, then how many minutes will it take to fill the tank?
|
[
"24",
"26",
"28",
"30",
"32"
] |
Let V be the volume of the tank.
The rate per minute at which the tank is filled is:
V/20 + V/12 - V/10 = V/30 per minute
The tank will be filled in 30 minutes.
The answer is D.
The answer is: D
|
D
|
mathematics
|
It was calculated that 100 men could complete a piece of work in 20 days. When work was scheduled to commence, it was found necessary to send 50 men to another project. How much longer will it take to complete the work?
|
[
"45 days.",
"40 days.",
"38 days.",
"35 days.",
"30 days."
] |
One day work = 1 / 20
One man’s one day work = 1 / ( 20 * 100)
Now:
No. Of workers = 50
One day work = 50 * 1 / ( 20 * 100)
The total no. of days required to complete the work = (100 * 20) / 50 = 40
Answer:B
The answer is: B
|
B
|
mathematics
|
A, B and C have Rs.500 between them, A and C together have Rs.200 and B and C Rs.350. How much does C have?
|
[
"50",
"45",
"20",
"73",
"27"
] |
A+B+C = 500
A+C = 200
B+C = 350
--------------
A+B+2C = 550
A+B+C = 500
----------------
C = 50
Answer:A
The answer is: A
|
A
|
mathematics
|
Two twins sisters Sita and Geeta were standing back to back and suddenly they started running in opposite directions for 2 km each. Then they turned left and ran for another 1.5 km.
What is the distance (in kilometers) between the the two twins when they stop?
|
[
"5",
"7",
"9",
"11",
"13"
] |
The distance between them is the hypotenuse of a right angle triangle with sides 3 km and 4 km.
hypotenuse = sqrt(3^2 + 4^2) = 5
The answer is A.
The answer is: A
|
A
|
mathematics
|
Two numbers are in the ratio of 2:3. If 20 be subtracted from each, they are in the ratio of 10:17. Find the numbers?
|
[
"70,105",
"60,88",
"80,120",
"60,84",
"60,81"
] |
(2x-20):(3x-20) =10:17
x = 35 => 70,105
Answer: A
The answer is: A
|
A
|
mathematics
|
The average age of seven persons sitting in a row facing east is 28 years. If the average age of the first three persons is 21 years and the average age of the last three persons is 34 years, then find the age of the person sitting in the middle of the row?
|
[
"31 years",
"78 years",
"27 years",
"11 years",
"87 years"
] |
Total age seven persons = (28 * 7)years
Total age of the first three persons and the last three persons are (21 * 3) years and (34 * 3) years respectively.
Age of the person sitting in the middle of the row
= 28 * 7 - 21 * 3 - 34 * 3 = 196 - 63 - 102
= 31 years.
Answer: B
The answer is: B
|
B
|
mathematics
|
In 1992 a total of 550 earthquakes occurred worldwide, some but not all of which occurred in Asia. If 150 of these earthquakes occurred in Asia, which of the following represents the ratio of the number of earthquakes that occurred in Asia to the number that did NOT occur in Asia?
|
[
"2/8",
"1/8",
"3/8",
"5/8",
"7/8"
] |
We're given a couple of facts to work with:
1) There were a total of 550 earthquakes
2) Of those earthquakes, 150 of them occurred in Asia
We're asked for the ratio of the number of earthquakes that occurred IN ASIA to the number of earthquakes that DID NOT occur in Asia.
Thus, there were 400 earthquakes that DID NOT occur in Asia....
The answer to the question is 150/400 = 3/8
Answer : C
The answer is: C
|
C
|
mathematics
|
If n = 2p, where p is a prime number greater than 2, how many different positiveevendivisors does n have, including n ?
|
[
"Two",
"Three",
"Four",
"Six",
"Eight"
] |
This is an interesting question because we are immediately given the option to insert any prime number we wish for p. Since this is a problem-solving question, and there can only be one correct answer, we can select any value for p, as long as it is a prime number greater than 2. We always want to work with small numbers, so we should select 3 for p. Thus, we have:
n = 4 x 3
n = 12
Next we have to determine all the factors, or divisors, of P. Remember the term factor is synonymous with the term divisor.
1, 12, 6, 2, 4, 3
From this we see that we have 4 even divisors: 12, 6, 2, and 4.
If you are concerned that trying just one value of p might not substantiate the answer, try another value for p. Let’s say p = 5, so
n = 4 x 5
n = 20
The divisors of 20 are: 1, 20, 2, 10, 4, 5. Of these, 4 are even: 20, 2, 10 and 4. As we can see, again we have 4 even divisors.
No matter what the value of p, as long as it is a prime number greater than 2, n will always have 4 even divisors.
The answer is A.
The answer is: A
|
A
|
mathematics
|
If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55, 60, then the average marks of all the students is:
|
[
"50",
"51.47",
"51.49",
"53",
"54.68"
] |
Required average
= (55 x 50 + 60 x 55 + 45 x 60)/(55 + 60 + 45)
= (2750 + 3300 + 2700)/160
= 8750/160
= 54.68
Answer is E
The answer is: E
|
E
|
mathematics
|
Simplify: (i) 12.05*5.4+0.6
|
[
"101.45",
"103.45",
"108.45",
"107.45",
"109.45"
] |
Given exp. = 12.05*(5.4/0.6) = (12.05*9) = 108.45
Answer is C.
The answer is: C
|
C
|
mathematics
|
Jerry went to a shop and bought things worth Rs. 20, out of which 30 % went on sales tax on taxable purchases. If the tax rate was 6%, then what was the cost of the tax free items?
|
[
"14",
"14.7",
"21.3",
"21.5",
"21.7"
] |
Total cost of the items he purchased = Rs.20
Given that out of this Rs.20, 30 % is given as tax
=> Total tax incurred = 30 % = Rs.30/100
Let the cost of the tax free items = x
Given that tax rate = 6%
∴ (20−30/100−x)6/100 = 30/100
⇒ 6(20 −0.3 −x) = 30
⇒ (20 − 0.3 − x) = 5
⇒ x = 20 − 0.3 − 5 = 14.7
B)
The answer is: B
|
B
|
mathematics
|
Of the three numbers, second is twice the first and is also thrice the third.If the average of the three numbers is 44.Find the largest number.
|
[
"70",
"72",
"66",
"74",
"71"
] |
Let the third number be x.
Then second number = 3x.
First number=3x/2.
Therefore x+3x+(3x/2)=(44*3) or x=24
So largest number= 2nd number=3x=72.
Answer is B.
The answer is: B
|
B
|
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