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mathematics | The population of a town is 45000; 5/9th of them are males and the rest females 40% of the males are married. What is the percentage of married females? | [
"56%",
"50%",
"57%",
"10%",
"80%"
]
| Male = 45,000* 5/9 = 25,000
Female = 45,000* 4/9 = 20,000
Married Male = 25,000* 40/100 = 10,000
Married Female = 10,000
20,000 ------------ 10,000
100 ------------- ? => 50%
Answer: B
The answer is: B | B |
mathematics | If x ≠ 0 and x^3 - (2- x^3)/x^3 = y/x^2, then y = | [
"-2-x",
"-2+x",
"-(x+2)",
"-2/x",
"1/x"
]
| x^3 - (2- x^3)/x^3 = y/x^2
-2/x^3 = y/x^2
y = -2/x
Answer : D
The answer is: D | D |
mathematics | A group of medical interns at Bohemus Medical School want to go on dates. There are 5 girls and 5 guys. Assuming girls go on dates with guys, how many possible ways can these 10 medical interns date each other? | [
"10",
"25",
"60",
"90",
"120"
]
| 1st girl can go with 5 guys
2nd girl can go with remaining 4
3rd girl can go with remaining 3 and so on
so the total ways are 5!= 120
E should be the answer
The answer is: E | E |
mathematics | 0, 2, 4, 8, 12, 18, 24, 32, ?
What number should replace the question mark? | [
"24",
"20",
"40",
"26",
"47"
]
| C 40
add 2, 2, 4, 4,6, 6,.....
The answer is: C | C |
mathematics | A no. when divided by 35leaves a remainder 20, what is the remainder if the same no.be divided by 15? | [
"2",
"4",
"7",
"8",
"9"
]
| Explanation:
35 + 25 = 60/15 = 4 (Remainder)
B
The answer is: B | B |
mathematics | W is an even integer greater than 300,000 and smaller than 1,000,000. How many numbers can W be? | [
"300,000",
"349,999",
"350,000",
"399,999",
"400,000"
]
| W 1,000,000-300,000=700,000 integers
700,000/2= 350,000 even integers.
350,000+1 inclusive. But since 1,000,000 and 300,000 are not included.
350,001-2=349,999
B
The answer is: B | B |
mathematics | If 5/2 artists make 5/2 paintings using 5/2 canvases in 5/2 days then how many artists r required to make 25 paintings using 25 canvases in 25 days? | [
"3/2",
"5/2",
"7/2",
"11/2",
"1/2"
]
| 5/2 artists make 5/2 paintings using 5/2 canvases in 5/2 days. So, 1 artist make 1 painting using 1 canvas in 5/2 days. So, 1/10 artist make 1 painting using 1 canvas in 25 days.
So, 25/10 (=5/2) artists make 25 paintings using 25 canvases in 25 days.
ANSWER:B
The answer is: B | B |
mathematics | 1600 men have provisions for 28 days in the temple. If after 4 days, 400 men leave the temple, how long will the food last now? | [
"76 days",
"98 days",
"32 days",
"45 days",
"24 days"
]
| 1600 ---- 28 days
1600 ---- 24
1200 ---- ?
1600*24 = 1200*x
x = 32 days
Answer: C
The answer is: C | C |
mathematics | If a1 = 1 and an+1= 2an + 5, n = 1, 2 .. , then a10 is equal to ? | [
"a. 6*2^9 -5",
"b. 5*2^99+6",
"c. 6*2^99+5",
"d. 6*2^99-5",
"e. 6*2^99-6"
]
| Here is solution:
an+1=2an+5............(1)
lets ADD 5 to both sides....
so (an+1) + 5= 2 (an+5)....................taking 2 as common factor
now a1=1. so for n=1, an+5=6.......
putting n=1. we get both sides as,
a2 + 5= 2 * 6 ..............as ( an+5=6 .......(for n=1)..)
a2= 2 *6 - 5
a2= 2 * 2 *3 - 5
a2= 2^2 *3 - 5................. so with same progression
a10= 2^10 * 3 - 5
a10=2* 2^9 * 3 - 5
a10= 6 * 2^9 - 5
A
The answer is: A | A |
mathematics | In the coordinate plane, points (x, 1) and (10, y) are on line k. If line k passes through the origin and has slope 1/4, then x + y = | [
"6.5",
"7",
"8",
"11",
"12"
]
| Line k passes through the origin and has slope 1/4 means that its equation is y=1/4*x.
Thus: (x, 1)=(4, 1) and (10, y) = (10,2.5) --> x+y=4+2.5=6.5
Answer: A.
The answer is: A | A |
mathematics | If the price of petrol increases by 25% and Bill intends to spend only an additional 15% on petrol, by how much % will he reduce the quantity of petrol purchased? | [
"A)8%",
"B)7%",
"C)10%",
"D)6%",
"E)9%"
]
| Explanation:
Assume that the initial price of 1 Litre petrol = Rs.100 ,Bill spends Rs.100 for petrol,
such that Bill buys 1 litre of petrol
After the increase by 25%, price of 1 Litre petrol = 100 × (100+25)/100 = Rs.125
Since Bill spends additional 15% on petrol,
amount spent by Bill = 100× (100+15)/100 = Rs.115
Hence Quantity of petrol that he can purchase = 115/125 Litre
Quantity of petrol reduced = (1−115/125) Litre
Percentage Quantity of reduction = (1−115125)/1 × 100 = 10/125 × 100 = 105 × 4 = 2 × 4 = 8%
Answer: Option A
The answer is: A | A |
mathematics | A train has a length of 150 meters . it is passing a man who is moving at 3 km/hr in the same direction of the train, in 3 seconds. Find out the speed of the train. | [
"182 km/hr",
"180 km/hr",
"152 km/hr",
"169 km/hr",
"183 km/hr"
]
| Explanation:
Length of the train, l = 150m
Speed of the man , Vm= 3 km/hr
Relative speed, Vr = total distance/time = (150/3) m/s = (150/3) × (18/5) = 180 km/hr
Relative Speed = Speed of train, Vt - Speed of man (As both are moving in the same direction)
=> 180 = Vt - 3
=> Vt = 180 + 3 = 183 km/hr
Answer: Option E
The answer is: E | E |
mathematics | Five years ago the average of the ages of A and B was 40 years and now the average of the ages of B and C is 49 years. What will be the age of the B ten years hence? | [
"39",
"23",
"28",
"98",
"26"
]
| Let the present ages of A, B and C be a, b and c respectively.
Given, [(a - 5) + (b - 5)] / 2 = 40 => a + b = 90 --- (1)
(b + c)/2 = 49 => b + c = 98 --- (2)
Answer: D
The answer is: D | D |
mathematics | When the integer n is divided by 8, the remainder is 5. Which of the following is NOT an even number? | [
"n + 3",
"n/2 + 3.5",
"n – 3",
"3n + 1",
"5n + 2"
]
| Given number = N =8p+5 ---> the number N is odd.
Thus ,
A. n + 3
n+3 = odd + odd = even. Thus not correct.
B. n/2 + 3.5
As n is odd, thus n/2 = abc.5 (where c = even) ---> abc.5+3.5 = abc+3+0.5+0.5 = even+odd+1= odd+1=even. Thus not correct.
C. n – 3
n-3 = odd - odd = even. Thus not correct.
D. 3n + 1
As n =odd, 3n=odd and 3n+1 = odd + odd = even. Thus not correct.
E. 5n + 2
As n =odd, 5n= odd --->5n+2 = odd + even = odd. Thus correct. ANSWER:E
The answer is: E | E |
mathematics | A grocer has a sale of Rs. 6435, Rs. 6927, Rs. 6855, Rs. 7230 and Rs. 6562 for 5 consecutive months. How much sale must he have in the sixth month so that he gets an average sale of Rs. 6500? | [
"Rs. 4991",
"Rs. 5991",
"Rs. 6991",
"Rs. 6001",
"None of these"
]
| Explanation:
Total sale for 5 months = Rs. (6435 + 6927 + 6855 + 7230 + 6562) = Rs. 34009.
Required sale = Rs. [ (6500 x 6) - 34009 ]
= Rs. (39000 - 34009)
= Rs. 4991.
Answer: A
The answer is: A | A |
mathematics | The average of 10 numbers is calculated as 5. It is discovered later on that while calculating the average, one number namely 36 was wrongly read as 26. The correct average is? | [
"2",
"3",
"4",
"5",
"6"
]
| 10 * 5 + 36 – 26 = 60/10 = 6
ANSWER:E
The answer is: E | E |
mathematics | What is the 101st digit after the decimal point in the decimal representation of 1/3 + 1/9 + 1/27 + 1/37? | [
"0",
"1",
"5",
"7",
"8"
]
| 1/3 + 1/9 + 1/27 = 13/27. = .481481…
1/37=.027027…
13/27 + 1/27 = .508508..
Hence 101st digit is 0.(3*33 +2=> hence the second digit of the recurring decimal which is 0)
Answer:A
The answer is: A | A |
mathematics | 2, 5, 10, 17, 26, ? | [
"35",
"36",
"48",
"49",
"37"
]
| The sequence is a series of squares+1,
1*1+1, 2*2+1, 3*3+1, 4*4+1, 5*5+1, 6*6+1=37
Answer : E.
The answer is: E | E |
mathematics | What is the sum of all the prime numbers greater than 30 but less than 50? | [
"126",
"199",
"198",
"188",
"122"
]
| Required sum = (31 + 37 + 41 + 43 + 47) = 199
Note: 1 is not a prime number
Answer B
The answer is: B | B |
mathematics | In expressing a length 81.475 km as nearly as possible with three significant digits, find the percentage error? | [
"0.075%",
"0.156%",
"0.031%",
"0.048%",
"0.152%"
]
| Error = 81.5-81.475 = 0.028
Required percentage = (0.028/81.475)*100 = 0.031%
Answer is C
The answer is: C | C |
mathematics | Rectangle ABCD is constructed in the coordinate plane parallel to the x- and y-axes. If the x- and y-coordinates of each of the points are integers which satisfy 6 ≤ x ≤ 11 and -5 ≤ y ≤ 5, how many possible ways are there to construct rectangle ABCD? | [
"396",
"1260",
"825",
"7920",
"15840"
]
| As the rectangle is parallel to coordinate axes, the coordinates of the points of the rectangle would be
(X1, Y1), (X2, Y1), (X2, Y2), (X1,Y2)
given that X1, X2 lie between 6 and 11..ie., 6 possible numbers
Possible combinations for X1,X2 would be 6C2 = 15
Similarly, Possible combinations for Y1, Y2 would be 11C2 = 55
Possible ways of constructing rectangle is by selecting any of the combination of X1,X2 and Y1,Y2
= 15 * 55 = 825
Ans. C
The answer is: C | C |
mathematics | Mr.Jones gave 40% of the money he had to his wife. he also gave 20% of the remaining amount to his 3 sons. half of the amount now left was spent on miscellaneous items and the remaining amount of Rs.12000 was deposited in the bank. how much money did Mr.jones have initially? | [
"100000",
"12000",
"15000",
"13000",
"65000"
]
| Let the initial amount with Mr.Jones be Rs.x
Then, (1/2)[100-(3*20)]% of x=12000
(1/2)*(40/100)*(60/100)*x=12000
x=((12000*25)/3)=100000
ANSWER A
The answer is: A | A |
mathematics | In a single throw of a die what is the probability of getting a number greater than 2 ? | [
"2/3",
"1/4",
"2/5",
"1/3",
"1/5"
]
| when a die is thrown S={1,2,3,4,5,6}
E = event of getting a number greater than 2 = {3,4,5,6}
P(E) = n(E)/n(S) = 4/6 = 2/3
Answer is A
The answer is: A | A |
mathematics | Printer P can print one lakh books in 8 hours. Printer Q can print the same number of books in 10 hours while Printer R can print the same in 12 hours. All the Printers started printing at 9 A.M. Printer P is stopped at 11 A.M. and the remaining 2printers complete work. Approximately at what time will the printing of 1 lac books be completed? | [
"10 pm",
"1 pm",
"12 pm",
"2 pm",
"3 pm"
]
| Work done by P in 1 hour = 1/8
Work done by Q in 1 hour = 1/10
Work done by R in 1 hour = 1/12
Work done by P,Q and R in 1 hour = 1/8 + 1/10 + 1/12 = 37/120
Work done by Q and R in 1 hour = 1/10 + 1/12 = 22/120 = 11/60
From 9 am to 11 am, all the Printer were operating.
Ie, they all operated for 2 hours and work completed = 2 × (37/120) = 37/60
Pending work = 1- 37/60 = 23/60
Hours taken by Q an R to complete the pending work = (23/60) / (11/60) = 23/11
which is approximately equal to 2
Hence the work will be completed approximately 2 hours after 11 am ; ie around 1 pm
B
The answer is: B | B |
mathematics | How many liters of pure alcohol is in a 5 liter bottle where the alcohol is at 30 percent? | [
"2.5",
"2",
"1",
"3",
"1.5"
]
| 5/10 = .5
.5 x 3 = 1.5
Answer is E
The answer is: E | E |
mathematics | a and b are two numbers selected randomly from 1,2,3.... 25 what is the probability of a and b are not equal. | [
"1/25",
"24/25",
"13/25",
"2/25",
"3/25"
]
| No of events=625((1,1),(1,2).......(25,25))
Probability of getting a&b are equal=(25/625)[(1,1),(2,2),(3,3).....(25,25)]
Probability of a and b or not equal=1-(25/625)
=600/625
=24/25
ANSWER:B
The answer is: B | B |
mathematics | Consider the sets Tn = {n, n + 1, n + 2, n + 3, n + 4}, where n = 1, 2, 3,...., 78. How many of these sets contain 6 or any integral multiple thereof (i.e., any one of the numbers 6, 12, 18, ...)? | [
"(a) 80",
"(b) 81",
"(c) 82",
"(d) 65",
"(e) 84"
]
| T1: 1,2,3,4,5
T2: 2,3,4,5,6
T3: 3,4,5,6,7
etc.
means that every multiple of 6 will be involved in 5 sets. We have (78-6)/6+1=13 such multiples.
So, final number of sets is 13*5=65
Answer: D
The answer is: D | D |
mathematics | A contractor undertakes to do a job within 100 days and hires 10 people to do it. After 20 days, he realizes that one fourth of the work is done so he fires 2 people. In how many more days W will the work get over? | [
"60",
"W=70",
"W=75",
"W=80",
"W=100"
]
| We can also use the concept of man-days here
100 days -->10men so the job includes 100*10=1000 man-days
After 20 days
1/4 of Job is completed so 1/4 X 1000 man-days=250 man-days Job is done
Now the Balance Job=1000-250=750 man-days worth of Job
Since 2 men are fired so B/L men=8
Therefore Total no. of days of Job=750 man-day/8 days = 375/4=94 days (approx.)
Now since this is total and Ques. is asking for additional no. of days,
So 94-20=74 days
The nearest approx. to answer is 75
Ans: C (75 days)
The answer is: C | C |
mathematics | Find the 2nd greatest number of five digits which is exactly divisible by 12, 15 and 18? | [
"A)13050",
"B)12960",
"C)14090",
"D)16200",
"E)12080"
]
| The largest five digit numbers are
16200,14090,13050,12960,12080,
16200 is divisible by 12, 15 and 18 ------(1st largest no)
14090 is not divisible by 12
13050 is not divisible by 12
12960 is divisible by 18, 12 and 15 -------(2nd largest)
12080 is not divisible by 12
ANSWER:B
The answer is: B | B |
mathematics | A seller of used cars has 10 cars to sell and each of his clients selected 2 cars that he liked most. If each car was selected exactly thrice, how many clients visited the garage? | [
"8",
"10",
"15",
"14",
"16"
]
| IfNo caris selected more than once then the number of clients = 10/2 =5
But since every car is being selected three times so No. of Clients must be thrice as well =5*3 = 15
Answer: option C
The answer is: C | C |
mathematics | x and y are positive integers. When x is divided by 6, the remainder is 3, and when x is divided by 16, the remainder is 5. When y is divided by 9, the remainder is 5, and when y is divided by 7, the remainder is 4. What is the least possible value of x / y? | [
"2.5",
"3",
"2",
"1.3",
"1.5"
]
| When x is divided by 6, the remainder is 3: So, the possible values of x are: 3, 9, 15, 21, etc.
When x is divided by 16, the remainder is 5: So, the possible values of x are: 5,21... STOP. Since both lists include 21, the smallest possible value of x is 21.
When y is divided by 9, the remainder is 5: So, the possible values of y are: 5, 14, 23,32 etc.
When y is divided by 7, the remainder is 4: So, the possible values of y are: 6, 14, ...STOP. Since both lists include 14, the smallest possible value of y is 14
Since the smallest possible values of x and y are 21 and 14 respectively, the smallest possible value of x / y is 1.5. So,E is the correct answer to the original question.
The answer is: E | E |
mathematics | 88% OF 370+24% OF 210-?=118 | [
"256",
"258",
"268",
"358",
"NONE OF THESE"
]
| LET 88% OF 370+240% OF 210-X=118
THEN, X=(88/100*370)+(24/100*210)-118-325.60+50.40-118=376-118=258
CORRECT OPTION: B
The answer is: B | B |
mathematics | The average height of 60 pupils in a class is 150 cm. Five of them whose height is 146 cm, leave the class and five others whose average height is 156 cm, join. The new average height of the pupils of the class (in cm) is ? | [
"287 cm",
"150.8 cm",
"276 cm",
"287 cm",
"297 cm"
]
| Total height = 150 * 60 = 9000 cm.
New average = [9000 - 5 * 146 + 5 * 156 ] / 60
= 150.8 cm.
Answer:B
The answer is: B | B |
mathematics | A man can row his boat with the stream at 6 km/h and against the stream in 4 km/h. The man's rate is? | [
"1 kmph",
"7 kmph",
"98 kmph",
"6 kmph",
"4 kmph"
]
| DS = 6
US = 4
S = ?
S = (6 - 4)/2 = 1 kmph
Answer: A
The answer is: A | A |
mathematics | Mohan purchased 15 kgs of rice at the rate of Rs.26 per kg and 8 kgs of pulses at the rate of Rs.26 per kg. Whaat is the total amount that he paid to the shopkeeper? | [
"Rs.598",
"Rs.594",
"Rs.596",
"Rs. 595",
"None of these"
]
| Explanation:
Price of 15 kgs of rice at Rs.26/kg = 15x26 = Rs.390
Price of 8 kgs of pulses at Rs.26/kg = 8x26 = Rs.208
Therefore, Total amount = Rs.390+Rs.208 = Rs.598.
Answer: Option A
The answer is: A | A |
mathematics | In a apartment, 30% of the people speak English, 20% speak Hindi and 10% speak both. If a people is selected at random, what is the probability that he has speak English or Hindi? | [
"1/3",
"2/3",
"2/5",
"2/7",
"2/9"
]
| P (E) = 30 / 100 = 3 / 10 , P (H) = 20 / 100 = 1 / 5 and P (E ∩ H) = 10 / 100 = 1 / 10
P (E or H) = P (E U H)
= P (E) + P (H) - P (E ∩ H)
= (3 / 10) + (1 / 5) - (1 / 10) = 4 / 10 = 2/5
C
The answer is: C | C |
mathematics | The sum of the smallest six digit number and the greatest five digit number is | [
"201110",
"199999",
"211110",
"1099999",
"None"
]
| Solution
Requires sum =(100000 + 99999)
=199999.
Answer B
The answer is: B | B |
mathematics | P is a prime number. If 6p is between 15 and 95, which of the following T can be a value of 7p + 2? | [
"T=15",
"T=79",
"121",
"65",
"21"
]
| [3,5,7,11,13] are prime numbers that fits this equation 15< 6X <95. Afterwards subtract 2 from all the answer n see if it's divisible by 7. Therefore A and E are out. Leaves out with B C D.
B =11
C =17
D = 9
Only 11 is the set of prime numbers that fit between 15 and 95. Therefore 79 is the answer.B
The answer is: B | B |
mathematics | A man's speed with the current is 22 km / hr and the speed of the current is 4 km / hr. The man's speed against the current is | [
"8.5 km / hr",
"9 km / hr",
"10 km / hr",
"14 km / hr",
"None"
]
| Sol.
Man's rate in still in water = (22 - 4) km / hr = 18 km / hr.
Man's rate against the current = (18 - 4) km / hr = 14 km / hr.
Answer D
The answer is: D | D |
mathematics | The area of a square field is 4802 m(power)2 the length of its diagonal is: | [
"98m",
"102m",
"95m",
"105m",
"96m"
]
| Let the diagonal be d metres,
Then 1/2 d(power)2 = 4802
d2 = 9604
d = √9604
d = 98 m
Answer is A.
The answer is: A | A |
mathematics | If 20% of a class averages 80% on a test, 50% of the class averages 60% on the test, and the remainder of the class averages 40% on the test, what is the overall class average? | [
"80%",
"74%",
"58%",
"56%",
"50%"
]
| 2 students scored 80%
5 students scored 60%
3 students scored 40%
(2)(80) + 5(60) + 3(40) =
160 + 300 + 120 =
580
580/10 students = 58 --> 58% average
ANSWER:C
The answer is: C | C |
mathematics | In a games hour 4 different types of players came to the ground? cricket 15, hokey 12, football 13, softball 15. How many players are present in the ground? | [
"70",
"52",
"55",
"49",
"50"
]
| total number of players= 15+12+13+15= 55
Answer is C
The answer is: C | C |
mathematics | Rs.590 is divided amongst A, B, C so that 5 times A's share, six times B's share and eight times C's share are all equal. Find C's share? | [
"Rs.157",
"Rs.150",
"Rs.289",
"Rs.128",
"Rs.129"
]
| A+B+C = 590
5A = 6B = 8C = x
A:B:C = 1/5:1/6:1/8
= 24:20:15
15/59 * 590 = Rs.150
Answer:B
The answer is: B | B |
mathematics | Find the average of all the numbers between 6 and 30 which are divisible by 4. | [
"15",
"18",
"20",
"22",
"None"
]
| Sol.
Average = (8+12+16+20+24+28 / 6) = 108 / 6 = 18
Answer B
The answer is: B | B |
mathematics | In a function they are distributing noble prize. In how many ways can 2 prizes be distributed among 5 boys when a boy gets any no. of prizes? | [
"25",
"30",
"64",
"70",
"80"
]
| Ans.(A)
Sol. In this case, repetitions are allowed, so all the two prizes can be given in 5 ways, i.e. (5 x 5) ways = 52 ways = 25 ways Or nr ways = 52 ways = 25 ways
The answer is: A | A |
mathematics | The set X = {7,8,9,10}. The set Y = {2,3,4,5}. We will randomly choose one element x from set X and one element y from set Y. What is the probability that x / y will be an integer? | [
"7/16",
"5/16",
"3/16",
"7/8",
"5/8"
]
| The total number of x and y pairs is 4*4=16.
There are five pairs such that x / y is an integer.
The probability that x / y is an integer is 5/16.
The answer is B.
The answer is: B | B |
mathematics | A sum of money triples itself in ten years at simple interest. Find the rate of interest? | [
"12 1/2 % p.a.",
"14 1/2 % p.a.",
"20 % p.a.",
"22 % p.a.",
"25 % p.a."
]
| Let the pricipal be Rs. x, then amount = 3x(where R = rate of interest) => Interest = 3x - x = Rs. 2x
R = (100 * 2x)/(x * 10) = 20 %
ANSWER:C
The answer is: C | C |
mathematics | Two men Amar and Bhuvan have the ratio of their monthly incomes as 6 : 5. The ratio of their monthly expenditures is 3 : 2. If Bhuvan saves one-fourth of his income, find the ratio of their monthly savings?
A. 3 : 5 | [
"3:9",
"3:10",
"3:21",
"3:12",
"3:14"
]
| Let the monthly incomes of Amar and Bhuvan be 6x and 5x respectively.
Let the monthly expenditure of Amar and Bhuvan be 3y and 2y respectively.
Savings of Bhuvan every month = 1/4(5x)
= (His income) - (His expenditure) = 5x - 2y.
=> 5x = 20x - 8y => y = 15x/8.
Ratio of savings of Amar and Bhuvan
= 6x - 3y : 1/4(5x) = 6x - 3(15x/8) : 5x/4 = 3x/8 : 5x/4
= 3 : 10.
Answer: Option B
The answer is: B | B |
mathematics | what is the sum of all 5 digits numbers which can be formed with the digits 0,1,2,3,4 without repetition | [
"2599980",
"2699980",
"2799980",
"2509980",
"2499980"
]
| There is a simplest formula for solving these type of questions when we are using numbers along with 0 for finding sum.
i,e........(sum of numbers)*{(n-1)!*(111...........n times)-(n-2)!*(111..........(n-1)times) }
so,here by putting the values as,
(0+1+2+3+4){(5-1)!*(11111)-(5-2)!*1111}
= 10{(4!*11111)-(3!*1111)}
= 10{266664-6666}
= 2599980
ANSWER:A
The answer is: A | A |
mathematics | What is the scope including 1/31+1/32+1/33+......+1/40? | [
"1/6~1/5",
"1/5~1/4",
"1/4~1/3",
"1/3~1/2",
"1/2~1"
]
| For Maximum value : It should be less than 1/31 + 1/31 +1/31... 10 times = 10/31 ~ 1/3
For Minimum Value : It should be greater than 1/40+ 1/40+ 1/40 .. 10 times = 10/40 = 1/4.
Thus, the answer should lie between 1/4 and 1/3. Correct ans : C.
The answer is: C | C |
mathematics | f n = 3^5 - 2^5, which of the following is NOT a factor of n? | [
"211",
"422",
"633",
"100",
"844"
]
| =243-32 =211 is prime number.any number not a factor of 211
D
The answer is: D | D |
mathematics | A retailer sells products that belong to different categories, A to F, in alphabetical order. The number of products sold in each category is distinct and in ascending order. If at-least 2 products are sold in any category and a total of 27 products were sold last week, what is the probability that a product sold last week belonged to Category D? | [
"2/27",
"4/27",
"5/27",
"8/27",
"15/27"
]
| there are 6 distinct categories..
Since each category has to have at least 2 products..
let A have 2 and each thereafter has ONE more than previous..
so A,B,C,D,E, and F will have minimum 2+3+4+5+6+7 = 7*8/2 -1 = 28-1 =27..
therefore ONLY possibility of products in each due to restriction of TOTAL as 27 is 2,3,4,5,6,7 so D will have 5 products..
Probability = 5/27
ANSWER:C
The answer is: C | C |
mathematics | A cistern is filled by pipe A in 16 hours and the full cistern can be leaked out by an exhaust pipe B in 20 hours. If both the pipes are opened, in what time the cistern is full? | [
"50hrs",
"60hrs",
"70hrs",
"80hrs",
"90hrs"
]
| time taken to full the cistern=(1/16-1/20)hrs
=1/80
=80hrs
ANSWER:D
The answer is: D | D |
mathematics | 2 pipes A and B can separately fill a cistern in 10 and 15 mins respectively. A person opens both the pipes together when the cistern should have been was full he findsthe waste pipe open. He then closes the waste pipe and in another 4 mins the cistern was full. In what time can the waste pipe empty the cistern when fill? | [
"6",
"8",
"10",
"12",
"14"
]
| 1/10 + 1/15 = 1/6 * 4 = 2/3
1 - 2/3 = 1/3
1/10 + 1/15 - 1/x = 1/3
x = 8
B
The answer is: B | B |
mathematics | How many words can be formed using the letters of the word “COMPANY”? | [
"1224",
"2434",
"3243",
"3435",
"5040"
]
| There are ‘7’ different letters of the word “COMPANY”
Number of Permutations taking all the letters at a time = 7P7
7!= 5040
E
The answer is: E | E |
mathematics | The average expenditure of a man for the first five months is Rs.120 and for the next seven months it is Rs.130. If he saves Rs.290 in that year, his monthly average income is : | [
"Rs.140",
"Rs.150",
"Rs.160",
"Rs.170",
"none"
]
| Explanation:
Total income = Rs.(120×5+130×7+290)=Rs.1800
Average monthly income
= Rs. (1800/12)=Rs.150
Correct Option: B
The answer is: B | B |
mathematics | For any integer p, *p is equal to the product of all the integers between 1 and p, inclusive. How many prime numbers are there between *5 + 3 and *5 + 5, inclusive? | [
"None",
"One",
"Two",
"Three",
"Four"
]
| Generally *p or p! will be divisible by ALL numbers from 1 to p. Therefore, *5 would be divisible by all numbers from 1 to 5.
=> *5+3 would give me a number which is a multiple of 3 and therefore divisible (since *5 is divisible by 3)
In fact adding anyprimenumber between 1 to 5 to *5 will definitely be divisible.
So the answer is none (A)!
Supposing if the question had asked for prime numbers between *5 + 3 and *5 + 11 then the answer would be 1. For *5 +3 and *5 + 13, it is 2 and so on...
A
The answer is: A | A |
mathematics | Lottery balls numbered consecutively from one through one hundred are placed in a spinner. If one ball is drawn at random, what is the probability that it will have the number 1 on it exactly once? | [
"9/100",
"1/10",
"11/100",
"19/100",
"1/5"
]
| Probability = No of balls with exactly one 1 / total number of balls
= {1,10,12 to 19, 21,31,41,51,61,71,81,91,100}/100
= 19/100
Answer is D
The answer is: D | D |
mathematics | A cylindrical water filter is filled with water at a rate of 11 cubic meters per hour, the level of water in the filter rises at a rate of 0.4 meters per hour. Which of the following best approximates the radius of the filter in meters? | [
"√10/2",
"√10",
"4.183",
"5",
"10"
]
| Here's my re-worked solution:
volume = 11 = pi (r^2)(0.4)
22 = 22/7 (4/10)(r^2)
70/4 = r^2
r = sqrt(70/4)
Ans: C
The answer is: C | C |
mathematics | 196, 144, 100, 64, 36, ? | [
"16",
"8",
"18",
"12",
"6"
]
| Explanation :
The pattern is 14^2, 12^2, 10^2, 8^2, 6^2, ...
So next number is 4^2 = 16
Answer : Option A
The answer is: A | A |
mathematics | A box contains 3 blue marbles, 4 red, 6 green marbles and 2 yellow marbles. If two marbles are picked at random, what is the probability that they are either blue or yellow? | [
"2/29",
"2/20",
"2/21",
"2/28",
"2/23"
]
| Given that there are three blue marbles, four red marbles, six green marbles and two yellow marbles. Probability that both marbles are blue = ³C₂/¹⁵C₂ = (3 * 2)/(15 * 14) = 1/35
Probability that both are yellow = ²C₂/¹⁵C₂
= (2 * 1)/(15 * 14) = 1/105
Probability that one blue and other is yellow
= (³C₁ * ²C₁)/¹⁵C₂ = (2 * 3 * 2)/(15 * 14)
= 2/35
Required probability = 1/35 + 1/105 + 2/35
= 3/35 + 1/105 = 1/35(3 + 1/3)
= 10/(3 * 35)
= 2/21
Answer:C
The answer is: C | C |
mathematics | Tough and Tricky questions: Percents.
Over the course of a year, a certain microbrewery increased its beer output by 60 percent. At the same time, it decreased its total working hours by 30 percent. By what percent did this factory increase its output per hour? | [
"228.5",
"228",
"229.5",
"220",
"229"
]
| Lets assume the initial production was 100 litres of beer for 100 hr.
With the 60% increase the total amount of beer production will be 160 litres and with 30 % decrease in total hours will be reduced to 70 hr.
100hr ----> 100 lts
1hr -----> 1 lts
70hr -----> 160 lts
1hr -----> 2.28 lts
Total Increase in production for 1 hr = 228%
Answer B
The answer is: B | B |
mathematics | A can complete a project in 20 days while B can complete same project in 30 days. If A and B start working together and A leaves the work 5 days before completion of project, then in how many days the project will be completed? | [
"15",
"19",
"20",
"21",
"22"
]
| A's 1day work=1/20;
B's 1day work=1/30;
(A+B) 1day work=(1/20+1/30)=1/12;
It is given that A leaves the work 5 days before completion of the project..
Thus,B alone does the remaining job in 5 days.
So,In 5 days ,B can do 1/6 w ..
Thus,(A+B) have worked (1-1/6)=5/6 w..
(A+B)can do 1/12 work in 1 day...
They did 5/6 w in 10 days.
Total days=(10+5) = 15
ANSWER:A
The answer is: A | A |
mathematics | The ratio between the length and the breadth of a rectangular park is 5 : 3. If a man cycling along the boundary of the park at the speed of 12 km/hr completes one round in 8 min, then thearea of the park (in sq. m) is? | [
"124545 m",
"134561 m",
"156787 m",
"15450 m",
"150000 m"
]
| Perimeter = Distance covered in 8 min. = 12000 x 8 m = 1600 m.
60
Let length = 5x metres and breadth = 3x metres.
Then, 2(5x + 3x) = 1600 or x = 100.
Length = 500 m and Breadth = 300 m.
Area = (500 x 300) m2 = 150000 m
E
The answer is: E | E |
mathematics | The length of a rectangular garden is three times its width. If the area of the rectangular garden is 675 square meters, then what is the width of the rectangular garden? | [
"14",
"15",
"16",
"17",
"18"
]
| Let x be the width of the garden.
3x^2 = 675
x^2 = 225
x = 15
The answer is B.
The answer is: B | B |
mathematics | Two stations A and B are 110 km apart on a straight line. One train starts from A at 7 a.m. and travels towards B at 20 kmph. Another train starts from B at 8 a.m. and travels towards A at a speed of 25 kmph. At what time will they meet? | [
"11",
"10",
"8",
"12",
"15"
]
| Suppose they meet x hours after 7 a.m.
Distance covered by A in x hours = 20x km.
Distance covered by B in (x - 1) hours = 25(x - 1) km.
Therefore 20x + 25(x - 1) = 110
45x = 135
x = 3.
So, they meet at 10 a.m.
Answer: B
The answer is: B | B |
mathematics | In an election between two candidates, the winner has a margin of 10% of the votes polled. If 3000 people change their mind and vote for the loser, the loser would have won by a margin of 10% of the votes polled. Find the total number of votes polled in the election? | [
"23000",
"22000",
"20000",
"25000",
"30000"
]
| Winner - Looser
55% - 45%
If 3000 people change their mind and vote for the loser:
Winner - Looser
45% - 55%
Thus 3,000 people compose 10% of all voters, which means that the total number of votes is 30,000.
Answer: E.
The answer is: E | E |
mathematics | Which of the following is closest to 10^170 – 10^30 ? | [
"10^210",
"10^180",
"10^170",
"10^90",
"10^6"
]
| 10^170 – 10^30
10^30 * (10^140 – 1)
as we know 10^2 - 1 means 100-1 and we get 99, which is approximately 100. hence (10^140 – 1) would remain as 10^140.
and 10^30 * 10^150 = 10^180. Answer is C.
The answer is: C | C |
mathematics | 9 spheres of the same size are made from melting a solid cylinder of 16 cm diameter and 12 cm height. What is the diameter of each sphere? | [
"4 cm",
"6 cm",
"8 cm",
"10 cm",
"12 cm"
]
| Volume of cylinder = pi*r^2*h
Volume of a sphere = 4*pi*R^3 / 3
9*4*pi*R^3 / 3 = pi*r^2*h
R^3 = r^2*h / 12 = 64 cm^3
R = 4 cm
D = 8 cm
The answer is C.
The answer is: C | C |
mathematics | Ramu bought an old car for Rs. 42000. He spent Rs. 13000 on repairs and sold it for Rs. 66900. What is his profit percent? | [
"17%",
"19%",
"18%",
"21.6%",
"16%"
]
| Total CP = Rs. 42000 + Rs. 13000
= Rs. 55000 and SP
= Rs. 66900
Profit(%) = (66900 - 55000)/55000 * 100
= 21.6%
Answer: D
The answer is: D | D |
mathematics | In how many ways can a committee consisting of 4 men and 5 women be formed from a group of 7 men and 10 women? | [
"7C4 10C5",
"4C7 5C10",
"7C5 9C4",
"9C4 7C5",
"NONE"
]
| Group consisting of 7 men and 10 women
4 men can be selected from 7 men in 7C4 ways
5 women can be selected from 10 women in 10C5 ways
Therefore, Total number of ways= 7C4 10C5
ANSWER:A
The answer is: A | A |
mathematics | If a sample of data has mean of 20 and SD of 3, which of the following values is more than 2.7 SDs from the mean? | [
"12.5",
"13",
"14",
"11.8",
"15"
]
| 2.7 SD's mean is equal to: +/- 2.7*3 = +/- 8.1
ie. 11.9 to 28.1
Answer is: D
The answer is: D | D |
mathematics | Find the least number when successively divided by 2, 3 and 7 leaves remainders 1, 2 and 3 respectively? | [
"22",
"65",
"28",
"27",
"19"
]
| Explanation:
2) 65 (32 3) 32 (10 7) 10 (1
64 30 7
-------- -------- - -----
1 2 3
=> 65
Answer: B
The answer is: B | B |
mathematics | When Alice entered the Forest of Forgetfulness, she forgot the day of
the week. She met the Lion and the Unicorn resting under a tree. The
Lion lies on Mondays, Tuesdays and Wednesdays and tells the truth
on the other days of the week. The Unicorn, on the other hand, lies
on Thursdays, Fridays, and Saturdays, but tells the truth on the other
days of the week. They made the following statements:
Lion: \Yesterday was one of my lying days."
Unicorn: \Yesterday was one of my lying days."
From these two statements, Alice was able to deduce the day of the
week. What day was it? | [
"Monday",
"Wednesday",
"Thursday",
"Friday",
"Sunday"
]
| If the Lion is telling the truth, the day of the week must be Thursday. If he
is lying, then the day of the week must be Monday. So the day of the week must be
either Thursday or Monday. If the Unicorn is telling the truth, the day of the week must
be Sunday. If he is lying, then the day of the week must be Thursday. The day of the
week cannot be Sunday (since we have already said that it must be Thursday or Monday).
Therefore, it must be Thursday
correct answer C
The answer is: C | C |
mathematics | In how many ways Chief Minister and Minister be elected from a team of 6 members? | [
"124",
"29",
"30",
"154",
"165"
]
| To do this, if captain is elected first, then we have 6 ways of doing this.
For election of vice-captain, we have only 5 ways left, coz 1 way is already consumed. (Situations like this is called dependent situation. One selection depends upon other selection.)
So, the ans is 6*5 = 30 ways.
C
The answer is: C | C |
mathematics | A sum was put at simple interest at certain rate for 3 years. Had it been put at 1% higher rate it would have fetched Rs. 78 more. The sum is: A. Rs. 2,400 B. Rs. 2,100 C. Rs. 2,200 D.Rs. 2,480 | [
"2000",
"2600",
"2200",
"2300",
"2400"
]
| 1 percent for 3 years= 78
1 percent for 1 year = 26
=> 100 percent = 2600
ANSWER:B
The answer is: B | B |
mathematics | If XY denotes X is raised to the power Y, Find the last two digits of 19413843+ 19614181 | [
"12",
"22",
"42",
"82",
"92"
]
| 1941^3843
unit digit= 1^3=1
10th digit=4*3=12=2 means last two digit =21
and 1961^4181
unit digit=1
10th digit=6*1=6 mean last two digit= 61
hence,
21+61= 82
ANSWER:D
The answer is: D | D |
mathematics | Seven children — A, B, C, D, E,— are going to sit in seven chairs in a row. The children CE have to sit next to each other, and the others can sit in any order in any remaining chairs. How many possible configurations are there for the children? | [
"600",
"720",
"48",
"4320",
"4800"
]
| for such questions , we can treat both as one then total person=4..
these 4 can be arranged in 4! ways.. but within these 4, one consists of two people who can be arranged in 2 ways CF or FC.. so ans =4!*2=48
ans C
The answer is: C | C |
mathematics | On June 1 a bicycle dealer noted that the number of bicycles in stock had decreased by 3 for each of the past 5 months. If the stock continues to decrease at the same rate for the rest of the year, how many fewer bicycles will be in stock on September 1 than were in stock on January 1? | [
"8",
"12",
"24",
"32",
"36"
]
| Jan 1 = C
Feb 1 = C - 3
March 1 = C - 6
April 1 = C - 9
May 1 = C - 12
June 1 = C - 15
July 1 = C - 18
Aug 1 = C - 21
Sept 1 = C - 24
Difference between stock on September 1 than were in stock on January 1 will be -
C - ( C - 24 )= 24
Hence answer will be (C)
The answer is: C | C |
mathematics | John bought 2 shares and sold them for $95 each. If he had a profit of 20% on the sale of one of the shares but a loss of 20% on the sale of the other share, then on the sale of both shares John had | [
"a profit of $10",
"a profit of $8",
"a loss of $8",
"a loss of $10",
"neither a profit nor a loss"
]
| $ Profit of the share sold at 20% profit =
120-95
20-?
$15 profit on the sale of 1 share.
$ Loss of the share sold at 20% loss=
80-95
20-?
$25 loss on the sale of 1 share.
15-25=Loss of $10
Answer: D
The answer is: D | D |
mathematics | A completes a work in 12 days and B complete the same work in 24 days. If both of them work together, then the number of days required to complete the work will be? | [
"8 days",
"11 days",
"21 days",
"22 days",
"24 days"
]
| If A can complete a work in x days and B can complete the same work in y days, then, both
of them together can complete the work in x y/ x+ y days
Therefore, here, the required number of days = 12 × 24/ 36 = 8 days.
Option 'A'
The answer is: A | A |
mathematics | Last year, Company Z made q dollars in profit. Half of the profit went to the company’s founder. The rest was split evenly among his two other partners. In terms of q, how much did each of the other partners receive? | [
"q/4",
"q/5",
"q/6",
"q/7",
"q/8"
]
| Profit = q
Profit to company founder = q/2
Profit to other partners = q/2
Number of other partners = 2
Profit to each partner = (q/2)/2 = q/4
Answer: A
The answer is: A | A |
mathematics | A rectangular farm has to be fenced one long side, one short side and the diagonal. If the cost of fencing is Rs.10 per meter. The area of farm is 1200 m2 and the short side is 30 m long. How much would the job cost? | [
"2387",
"1298",
"1128",
"1237",
"1200"
]
| l * 30 = 1200 l = 40
40 + 30 + 50 = 120
120 * 10 = 1200
E
The answer is: E | E |
mathematics | What will be the least number which when doubled will be exactly divisible by 12, 18, 21 and 30? | [
"228",
"630",
"998",
"267",
"212"
]
| L.C.M of 12, 18, 21, 30
= 2 * 3 * 2 * 3 * 7 * 5 = 1260
Required number = 1260/2 = 630.
Answer:B
The answer is: B | B |
mathematics | Identify the next two numbers in this Sequence ?
101, 112, 131, 415, 161, 718, ???, ??? | [
"123005",
"456804",
"545788",
"342678",
"192021"
]
| E
192 021
If you look at it as two-digit numbers you'll see:10 11 12 13 14 15 16 17 18 19 20 21
The answer is: E | E |
mathematics | Increasing the original price of an article by 15 percent and then increasing the new price by 15 percent is equivalent to increasing the original price by | [
"32.25%",
"31.00%",
"30.25%",
"30.00%",
"22.50%"
]
| You can do this by approximation, or with straight math by calculating 100*1.15^2.
Or step by step: if you increase 100 by 15% you'll get 115, then if you increase 115=100+15 by 15% again, 100 will gain 15 again and 15 will gain its 15% which is 2.25, so total gain is 15+2.25=17.25 --> 115+17.25=132.25.
Answer: A.
The answer is: A | A |
mathematics | A person spends 1/3rd of the money with him on clothes, 1/5th of the remaining on food and 1/4th of the remaining on travel. Now, he is left with Rs 300. How much did he have with him in the beginning? | [
"s 200",
"s 750",
"s 300",
"s 450",
"s 550"
]
| Suppose the amount in the beginning was Rs ’x’
Money spent on clothes = Rs 1x/3 Balance = Rs 2x/3
Money spent on food = 1/5 of 2x/3 = Rs 2x/15
Balance = 2x/3 - 2x/15 = Rs 8x/15
Money spent on travel = 1/4 of 8x/15 = Rs 2x/15 = 8x/15 - 2x/15 = 6x/15 = Rs2x/5
Therefore 2x/5 = 300 = 750
ANSWER:B
The answer is: B | B |
mathematics | The speed of a subway train is represented by the equation z=s^2+2s for all situations where 0≤s≤7, where z is the rate of speed in kilometers per hour and s is the time in seconds from the moment the train starts moving. In kilometers per hour, how much faster is the subway train moving after 7 seconds than it was moving after 5 seconds? | [
"4",
"28",
"15",
"48",
"63"
]
| Given: z=s^2+2s for 0≤s≤7
z(5) = 5^2 + 2*5 = 35
z(7) = 7^2 + 2*7 = 63
Therefore z(7) - z(3) = 63 - 35 = 28 km/hr
Option B
The answer is: B | B |
mathematics | Two cars cover the same distance at the speed of 32 and 64 kmps respectively. Find the distance traveled by them if the slower car takes 1 hour more than the faster car. | [
"73",
"38",
"64",
"83",
"93"
]
| Explanation:
32(x + 1) = 64x
X = 1
32 * 2 = 64 km
Answer: Option C
The answer is: C | C |
mathematics | A, B and C shared the profit in a business in the ratio 5 : 7 : 8. They had partnered for 14 months, 10 months and 7 months respectively. What was the ratio of their investments? | [
"10:12:14",
"12:24:28",
"20:22:12",
"25:49:80",
"None of these"
]
| Explanation :
Ratio in which A,B and C shared the profit = 5 : 7 : 8
Assume that the ratio of their investment = a:b:c
Then 14a : 10b : 7c = 5 : 7 : 8
Good to go, we got the equation. Now it's a matter of time to find a, b and c
14a/10b = 5/7
=> 98a = 50b
=> b = 98a/50 = 49a/25 ---(1)
14a/7c =5/8
=> 2a/c =5/8
=> 16a = 5c
=> c = 16a/5 ---(2)
a : b : c = a : 49a/25 : 16a/5 = 1 : 49/25 : 16/5 = 25 : 49 : 80. Answer : Option D
The answer is: D | D |
mathematics | What is the greatest value of positive integer x such that 2^x is a factor of 100^70? | [
"120",
"140",
"130",
"150",
"160"
]
| Put in simple words, we need to find the highest power of 2 in 100^70
100 = 2^2*5^2
Therefore 100^70 = (2^2*5^2)^70 = 2^140*5^140
Answer : B
The answer is: B | B |
mathematics | Two trains of equal lengths take 10 sec and 15 sec respectively to cross a telegraph post. If the length of each train be 140 m, in what time will they cross other travelling in opposite direction? | [
"17 sec",
"12 sec",
"16 sec",
"14 sec",
"18 sec"
]
| Speed of the first train = 120/10 = 12 m/sec.
Speed of the second train = 120/5 = 8 m/sec.
Relative speed = 12 + 8 = 20 m/sec.
Required time = (140 + 140)/20 = 14 sec.
Answer:D
The answer is: D | D |
mathematics | The greatest number by which the product of three consecutive multiples of 4 is always | [
"384",
"81",
"162",
"243",
"None of these"
]
| Explanation:
4*8*12 = 384
Option A
The answer is: A | A |
mathematics | Cindy paddles her kayak upstream at x kilometers per hour, and then returns downstream the same distance at n kilometers per hour. How many kilometers upstream did she travel if she spent a total of p hours for the round trip? | [
"mnp",
"mn/p",
"(x + n)/p",
"xnp/(x + n)",
"px/n- pn/x"
]
| let t1 and t2 be the time taken to row upstream and downstream respectively
now,
t1=distance/speed=d/x
similarly,
t2=d/n (as same distance has to be rowed)
also,
t1+t2=p
therefore,
p=(d/x)+(d/n)
=d(x+n)/xn
d=pxn/(x+n)=D
The answer is: D | D |
mathematics | Rs.8000 become Rs.9261 in a certain interval of time at the rate of 5% per annum of C.I. Find the time? | [
"2",
"9",
"8",
"3",
"5"
]
| n:
9261 = 8000(21/20)N
(21/20)3 = (21/20)N => N = 3
Answer:D
The answer is: D | D |
mathematics | On dividing 109 by a number, the quotient is 9 and the remainder is 1. Find the divisor? | [
"10",
"12",
"14",
"16",
"18"
]
| d = (D-R)/Q
= (109 - 1)/9
= 108/9 = 12
B)
The answer is: B | B |
mathematics | A single discount equivalent to the discount series of 20%, 10% and 5% is? | [
"31.9",
"31.2",
"31.6",
"71.2",
"31.1"
]
| 100*(80/100)*(90/100)*(95/100) = 68.4
100 - 68.4 = 31.6'
Answer: C
The answer is: C | C |
mathematics | Two water pumps, working simultaneously at their respective constant rates, took exactly 9 hours to fill a swimming pool. If the constant rate of one pump was 1.5 times the constant rate of the other, how many hours would it have taken the faster pump to fill the pool if it had worked alone at its constant rate? | [
"12",
"14",
"15",
"16",
"18"
]
| Let the rate of the slow pump be x. Then the rate of the fast pump is 1.5x.
(x+1.5x) = 2.5x = 1/9 of the capacity of the whole pool per hour.
The rate of the fast pump is (1.5/2.5)*1/9 = 1/15 of the whole pool per hour.
The time it takes the faster pump to fill the pool would be 15 hours.
The answer is C.
The answer is: C | C |
mathematics | If the set S is composed of the following numbers {99, 100, 100, 105, 106, 111, 128}, which of the following is largest? | [
"The average (arithmetic mean) of set S",
"The median of set S",
"The mode of set S",
"The range of set S",
"The standard deviation of set S"
]
| A) 99, 100, 100, 105, 106, 111, 128 = 749 and its mean is 749/7 = 107.
B) The list is of 7 numbers and median is 105.
C) Mode is number of repetition of a number in the list , here it is 100.
D) Range = Max value - min value = 128 -99 = 29.
E) SD = square root of (sum of ( mean of series - number)^2 ) / n =>< 100
IMO option A is correct answer..
The answer is: A | A |
mathematics | Peter invested a certain sum of money in a simple interest bond whose value grew to $400 at the end of 3 years and to $ 600 at the end of another 2 years. What was the rate of interest in which he invested his sum? | [
"100%",
"12.5%",
"67%",
"25%",
"33%"
]
| Lets assume the Principal Amount (initial amount invested) to be P
rate of interest to beRand time as T. We need to find R
Now After a time of 3years the principal P amounts to $400 and after a time of 5years ( question says after another 5years so 3+2) P becomes $600.
Formulating the above data
Amount (A1) at end of 3years
A1= P(1 + 3R/100) = 400
Amount (A2) at end of 8years
A2 = P(1 + 5R/100) = 600
Dividing A2 by A1 we get
(1 + 5R/100)/(1 + 3R/100) = 6/8
after cross multiplication we are left with R =100
Option: A
The answer is: A | A |
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