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22,900
Given $$\frac {\sin\alpha-2\cos\alpha}{\sin\alpha +2\cos\alpha}=3,$$ calculate: (1) $$\frac {\sin\alpha+2\cos\alpha}{5\cos\alpha -\sin\alpha};$$ (2) $({\sin\alpha+\cos\alpha})^{2}.$
\frac{9}{17}
99.21875
22,901
My friend June likes numbers that have an interesting property: they are divisible by 4. How many different pairings of last two digits are possible in numbers that June likes?
25
85.15625
22,902
The ferry boat begins transporting tourists to an island every hour starting at 9 AM until its last trip, which starts at 4 PM. On the first trip at 9 AM, there were 120 tourists, and on each successive trip, there were 2 fewer tourists than on the previous trip. Determine the total number of tourists the ferry transported to the island that day.
904
11.71875
22,903
In the plane rectangular coordinate system $xOy$, the parameter equations of the line $l$ are $\left\{\begin{array}{l}x=1+\frac{{\sqrt{2}}}{2}t\\ y=\frac{{\sqrt{2}}}{2}t\end{array}\right.$ (where $t$ is the parameter). Taking the coordinate origin $O$ as the pole and the positive half-axis of the $x$-axis as the polar axis, establishing a polar coordinate system with the same unit length, the polar coordinate equation of the curve $C$ is $ρ=2\sqrt{2}\sin({θ+\frac{π}{4}})$. $(1)$ Find the general equation of the line $l$ and the rectangular coordinate equation of the curve $C$; $(2)$ Let point $P(4,3)$, the intersection points of line $l$ and curve $C$ be $A$ and $B$, find the value of $\frac{1}{{|{PA}|}}+\frac{1}{{|{PB}|}}$.
\frac{{5\sqrt{2}}}{{11}}
0
22,904
The graph of the function $f(x)=\sin (2x+\varphi )$ $(|\varphi| < \frac{\pi}{2})$ is shifted to the left by $\frac{\pi}{6}$ units and becomes an even function. Let the sequence $\{a_n\}$ be defined by the formula $a_n=f(\frac{n\pi}{6})$. Compute the sum of the first $2018$ terms of $\{a_n\}$.
\frac{3}{2}
79.6875
22,905
A right circular cone is sliced into five pieces by planes parallel to its base. All of these pieces have the same height. What is the ratio of the volume of the third-largest piece to the volume of the largest piece?
\frac{19}{61}
30.46875
22,906
Regular octagonal pyramid $\allowbreak PABCDEFGH$ has the octagon $ABCDEFGH$ as its base. Each side of the octagon has length 5. Pyramid $PABCDEFGH$ has an additional feature where triangle $PAD$ is an equilateral triangle with side length 10. Calculate the volume of the pyramid.
\frac{250\sqrt{3}(1 + \sqrt{2})}{3}
4.6875
22,907
If I have a $5 \times 5$ chess board, in how many ways can I place five distinct pawns on the board such that each column and row of the board contains no more than one pawn?
14400
0
22,908
Boys and girls are standing in a circle (there are both), a total of 20 children. It is known that each boy's neighbor in the clockwise direction is a child in a blue T-shirt, and each girl's neighbor in the counterclockwise direction is a child in a red T-shirt. Can you uniquely determine how many boys are in the circle?
10
85.15625
22,909
In a rectangular grid comprising 5 rows and 4 columns of squares, how many different rectangles can be traced using the lines in the grid?
60
1.5625
22,910
How many positive integers have cube roots that are less than 20?
7999
90.625
22,911
Distribute 7 students into two dormitories, A and B, with each dormitory having at least 2 students. How many different distribution plans are there?
112
32.8125
22,912
Given the ellipse $C\_1$: $\frac{x^{2}}{a^{2}}+ \frac{y^{2}}{b^{2}}=1 (a > b > 0)$ and the hyperbola $C\_2$: $x^{2}- \frac{y^{2}}{4}=1$ share a common focus. One of the asymptotes of $C\_2$ intersects with the circle having the major axis of $C\_1$ as its diameter at points $A$ and $B$. If $C\_1$ precisely trisects the line segment $AB$, then the length of the minor axis of the ellipse $C\_1$ is _____.
\sqrt{2}
33.59375
22,913
Given $\triangle ABC$ with $AC=1$, $\angle ABC= \frac{2\pi}{3}$, $\angle BAC=x$, let $f(x)= \overrightarrow{AB} \cdot \overrightarrow{BC}$. $(1)$ Find the analytical expression of $f(x)$ and indicate its domain; $(2)$ Let $g(x)=6mf(x)+1$ $(m < 0)$, if the range of $g(x)$ is $\left[- \frac{3}{2},1\right)$, find the value of the real number $m$.
- \frac{5}{2}
18.75
22,914
Define the operation "" such that $ab = a^2 + 2ab - b^2$. Let the function $f(x) = x2$, and the equation $f(x) = \lg|x + 2|$ (where $x \neq -2$) has exactly four distinct real roots $x_1, x_2, x_3, x_4$. Find the value of $x_1 + x_2 + x_3 + x_4$.
-8
27.34375
22,915
What is the least positive integer $n$ such that $6375$ is a factor of $n!$?
17
24.21875
22,916
Given a circle $C: (x-1)^{2} + (y-2)^{2} = 25$ and a line $l: (2m+1)x + (m+1)y - 7m-4 = 0$, where $m \in \mathbb{R}$. Find the minimum value of the chord length $|AB|$ cut by line $l$ on circle $C$.
4\sqrt{5}
31.25
22,917
Let $f(x) = 4\cos(wx+\frac{\pi}{6})\sin(wx) - \cos(2wx) + 1$, where $0 < w < 2$. 1. If $x = \frac{\pi}{4}$ is a symmetry axis of the function $f(x)$, find the period $T$ of the function. 2. If the function $f(x)$ is increasing on the interval $[-\frac{\pi}{6}, \frac{\pi}{3}]$, find the maximum value of $w$.
\frac{3}{4}
47.65625
22,918
Evaluate the expression $2000 \times 1995 \times 0.1995 - 10$.
0.2 \times 1995^2 - 10
0
22,919
In the complex plane, let $A$ be the set of solutions to $z^3 - 27 = 0$ and let $B$ be the set of solutions to $z^3 - 9z^2 - 27z + 243 = 0,$ find the distance between the point in $A$ closest to the origin and the point in $B$ closest to the origin.
3(\sqrt{3} - 1)
7.03125
22,920
Given a geometric sequence $\{a_n\}$ satisfies $a_2a_5=2a_3$, and $a_4$, $\frac{5}{4}$, $2a_7$ form an arithmetic sequence, the maximum value of $a_1a_2a_3…a_n$ is \_\_\_\_\_\_.
1024
59.375
22,921
During a space experiment conducted by astronauts, they must implement a sequence of 6 procedures. Among them, Procedure A can only occur as the first or the last step, and Procedures B and C must be adjacent when conducted. How many different sequences are there to arrange the experiment procedures?
96
78.90625
22,922
Every 1 kilogram of soybeans can produce 0.8 kilograms of soybean oil. With 20 kilograms of soybeans, you can produce \_\_\_\_\_\_ kilograms of soybean oil. To obtain 20 kilograms of soybean oil, you need \_\_\_\_\_\_ kilograms of soybeans.
25
44.53125
22,923
Given the vertex of angle α is at the origin of the coordinate system, its initial side coincides with the non-negative half-axis of the x-axis, and its terminal side passes through the point (-√3,2), find the value of tan(α - π/6).
-3\sqrt{3}
86.71875
22,924
What is the greatest number of consecutive integers whose sum is $36$?
72
0
22,925
The line $10x + 8y = 80$ forms a triangle with the coordinate axes. What is the sum of the lengths of the altitudes of this triangle? A) $\frac{18\sqrt{41} + 40}{\sqrt{41}}$ B) $\frac{360}{17}$ C) $\frac{107}{5}$ D) $\frac{43}{2}$ E) $\frac{281}{13}$
\frac{18\sqrt{41} + 40}{\sqrt{41}}
65.625
22,926
Let \( F_1 = (0,2) \) and \( F_2 = (6,2) \). Find the set of points \( P \) such that \[ PF_1 + PF_2 = 10 \] forms an ellipse. The equation of this ellipse can be written as \[ \frac{(x - h)^2}{a^2} + \frac{(y - k)^2}{b^2} = 1. \] Find \( h + k + a + b \).
14
94.53125
22,927
Egor, Nikita, and Innokentiy took turns playing chess with each other (two play, one watches). After each game, the loser gave up their spot to the spectator (there were no draws). It turned out that Egor participated in 13 games, and Nikita in 27 games. How many games did Innokentiy play?
14
10.15625
22,928
In right triangle $DEF$ with $\angle D = 90^\circ$, we have $DE = 8$ and $EF = 17$. Find $\cos F$.
\frac{8}{17}
2.34375
22,929
It is known that the distance between any two of the given $n(n=2,3,4,5)$ points in the plane is at least 1. What is the minimum value that the diameter of this system of points can have?
\sqrt{2}
3.90625
22,930
Given: $A=2a^{2}-5ab+3b$, $B=4a^{2}+6ab+8a$. $(1)$ Simplify: $2A-B$; $(2)$ If $a=-1$, $b=2$, find the value of $2A-B$; $(3)$ If the value of the algebraic expression $2A-B$ is independent of $a$, find the value of $b$.
-\frac{1}{2}
90.625
22,931
Let \( Q_1 \) be a regular \( t \)-gon and \( Q_2 \) be a regular \( u \)-gon \((t \geq u \geq 3)\) such that each interior angle of \( Q_1 \) is \( \frac{60}{59} \) as large as each interior angle of \( Q_2 \). What is the largest possible value of \( u \)?
119
57.8125
22,932
In the rectangular coordinate system on a plane, the parametric equations of curve $C$ are given by $\begin{cases} x = 2\cos θ \\ y = \sqrt{3}\sin θ \end{cases}$ ($θ$ is the parameter). A polar coordinate system is established with the coordinate origin as the pole and the positive half of the $x$-axis as the polar axis. The line $l$ passes through two points $A(\sqrt{2}, \frac{π}{4})$ and $B(3, \frac{π}{2})$ in the polar coordinate system. (I) Write the general equation of curve $C$ and find the slope of line $l$. (II) Suppose line $l$ intersects curve $C$ at points $P$ and $Q$. Compute $|BP| \cdot |BQ|$.
\frac{120}{19}
11.71875
22,933
Given the functions f(x) = x and g(x) = ax^2 - x, where a > 0. If for all x1 in the interval [1, 2], there exists an x2 in the interval [1, 2] such that f(x1) * f(x2) = g(x1) * g(x2) holds true, then find the value of a.
\frac{3}{2}
44.53125
22,934
A certain store sells a type of handbag, and it is known that the cost price of this handbag is $50$ yuan per unit. Market research shows that the daily sales quantity $y$ (unit: units) of this handbag is related to the selling price $x$ (unit: yuan) as follows: $y=-x+80$ $(50 < x < 80)$. Let $w$ represent the daily sales profit of this handbag.<br/>$(1)$ At what price should the selling price of this handbag be set for the store to maximize its daily sales profit? What is the maximum profit per day?<br/>$(2)$ If the price department stipulates that the selling price of this handbag should not exceed $68$ yuan, and the store needs to make a daily sales profit of $200$ yuan from selling this handbag, what should be the selling price per unit?
60
93.75
22,935
In $\triangle ABC$, $a$, $b$, $c$ are the lengths of the sides opposite to $\angle A$, $\angle B$, $\angle C$ respectively. It is known that $a$, $b$, $c$ are in geometric progression, and $a^{2}-c^{2}=ac-bc$, (1) Find the measure of $\angle A$; (2) Find the value of $\frac{b\sin B}{c}$.
\frac{\sqrt{3}}{2}
42.96875
22,936
Arrange 3 boys and 4 girls in a row. Calculate the number of different arrangements under the following conditions: (1) Person A and Person B must stand at the two ends; (2) All boys must stand together; (3) No two boys stand next to each other; (4) Exactly one person stands between Person A and Person B.
1200
9.375
22,937
A pyramid is intersected by a plane parallel to its base, dividing its lateral surface into two parts of equal area. In what ratio does this plane divide the lateral edges of the pyramid?
\frac{1}{\sqrt{2}}
0.78125
22,938
Simplify the product \[\frac{9}{5}\cdot\frac{14}{9}\cdot\frac{19}{14} \dotsm \frac{5n+4}{5n-1} \dotsm \frac{1009}{1004}.\]
\frac{1009}{5}
66.40625
22,939
To welcome the 2008 Olympic Games, a craft factory plans to produce the Olympic logo "China Seal" and the Olympic mascot "Fuwa". The factory mainly uses two types of materials, A and B. It is known that producing a set of the Olympic logo requires 4 boxes of material A and 3 boxes of material B, and producing a set of the Olympic mascot requires 5 boxes of material A and 10 boxes of material B. The factory has purchased 20,000 boxes of material A and 30,000 boxes of material B. If all the purchased materials are used up, how many sets of the Olympic logo and Olympic mascots can the factory produce?
2400
0.78125
22,940
Given functions $y_1=\frac{k_1}{x}$ and $y_{2}=k_{2}x+b$ ($k_{1}$, $k_{2}$, $b$ are constants, $k_{1}k_{2}\neq 0$).<br/>$(1)$ If the graphs of the two functions intersect at points $A(1,4)$ and $B(a,1)$, find the expressions of functions $y_{1}$ and $y_{2}$.<br/>$(2)$ If point $C(-1,n)$ is translated $6$ units upwards and falls exactly on function $y_{1}$, and point $C(-1,n)$ is translated $2$ units to the right and falls exactly on function $y_{2}$, and $k_{1}+k_{2}=0$, find the value of $b$.
-6
78.125
22,941
In $\triangle ABC$, $a$, $b$, $c$ are the sides opposite to angles $A$, $B$, $C$ respectively, and $a=2$, $b=3$, $\cos C=\frac{1}{3}$. The radius of the circumcircle is ______.
\frac{9 \sqrt{2}}{8}
89.84375
22,942
How many distinct four-digit numbers are divisible by 5 and have 45 as their last two digits?
90
92.96875
22,943
In the Cartesian coordinate plane $(xOy)$, the focus of the parabola $y^{2}=2x$ is $F$. Let $M$ be a moving point on the parabola, then the maximum value of $\frac{MO}{MF}$ is _______.
\frac{2\sqrt{3}}{3}
33.59375
22,944
Given the graph of the power function $y=f(x)$ passes through the point $\left(\frac{1}{3},\frac{\sqrt{3}}{3}\right)$, then the value of $\log_{2}f(2)$ is \_\_\_\_.
\frac{1}{2}
88.28125
22,945
What is the least positive integer $m$ such that the following is true? *Given $\it m$ integers between $\it1$ and $\it{2023},$ inclusive, there must exist two of them $\it a, b$ such that $1 < \frac ab \le 2.$*
12
35.9375
22,946
Given every 8-digit whole number is a possible telephone number except those that begin with 0 or 1, or end in 9, determine the fraction of these telephone numbers that begin with 9 and end with 0.
\frac{1}{72}
93.75
22,947
After shifting the graph of the function $y=\sin^2x-\cos^2x$ to the right by $m$ units, the resulting graph is symmetric to the graph of $y=k\sin x\cos x$ ($k>0$) with respect to the point $\left( \frac{\pi}{3}, 0 \right)$. Find the minimum positive value of $k+m$.
2+ \frac{5\pi}{12}
7.03125
22,948
What is the probability that the same number will be facing up on each of five standard six-sided dice that are tossed simultaneously? Express your answer as a simplified common fraction.
\frac{1}{1296}
95.3125
22,949
Let $f(x)$ be an odd function on $R$, $f(x+2)=-f(x)$. When $0\leqslant x\leqslant 1$, $f(x)=x$. Find $f(5.5)$.
0.5
47.65625
22,950
A circular cylindrical post has a circumference of 6 feet and a height of 18 feet. A string is wrapped around the post which spirals evenly from the bottom to the top, looping around the post exactly six times. What is the length of the string, in feet?
18\sqrt{5}
82.03125
22,951
Simplify first, then evaluate: $\left(2m+n\right)\left(2m-n\right)-\left(2m-n\right)^{2}+2n\left(m+n\right)$, where $m=2$, $n=-1^{2023}$.
-12
86.71875
22,952
The total in-store price for a laptop is $299.99. A radio advertisement offers the same laptop for five easy payments of $55.98 and a one-time shipping and handling charge of $12.99. Calculate the amount of money saved by purchasing the laptop from the radio advertiser.
710
0
22,953
Given a fixed integer \( n \) where \( n \geq 2 \): a) Determine the smallest constant \( c \) such that the inequality \(\sum_{1 \leq i < j \leq n} x_i x_j (x_i^2 + x_j^2) \leq c \left( \sum_{i=1}^n x_i \right)^4\) holds for all nonnegative real numbers \( x_1, x_2, \ldots, x_n \geq 0 \). b) For this constant \( c \), determine the necessary and sufficient conditions for equality to hold.
\frac{1}{8}
60.15625
22,954
Two circles of radius 3 are centered at $(3,0)$ and at $(0,3)$. Determine the area of their overlapping interiors. Express your answer in expanded form in terms of $\pi$.
\frac{9}{2}\pi - 9
0
22,955
Given the set $A=\{m+2, 2m^2+m\}$, if $3 \in A$, then the value of $m$ is \_\_\_\_\_\_.
-\frac{3}{2}
24.21875
22,956
Given the function $f(\cos x) = -f'(\frac{1}{2})\cos x + \sqrt{3}\sin^2 x$, find the value of $f(\frac{1}{2})$.
\sqrt{3}
75.78125
22,957
Given that $α$ is an angle in the second quadrant and $\sin α= \frac {3}{5}$, find $\sin 2α$.
- \frac{24}{25}
99.21875
22,958
In a trapezoid, the two non parallel sides and a base have length $1$ , while the other base and both the diagonals have length $a$ . Find the value of $a$ .
\frac{\sqrt{5} + 1}{2}
0
22,959
Given $\sin \left(x+ \frac {\pi}{3}\right)= \frac {1}{3}$, then the value of $\sin \left( \frac {5\pi}{3}-x\right)-\cos \left(2x- \frac {\pi}{3}\right)$ is \_\_\_\_\_\_.
\frac {4}{9}
78.90625
22,960
Express $0.000 000 04$ in scientific notation.
4 \times 10^{-8}
36.71875
22,961
A taxi driver passes through six traffic checkpoints on the way from the restaurant to the train station. Assuming that the events of encountering a red light at each checkpoint are independent of each other and the probability is $\frac{1}{3}$ at each checkpoint, calculate the probability that the driver has passed two checkpoints before encountering a red light.
\frac{4}{27}
38.28125
22,962
Given an arithmetic sequence $\{a_n\}$ with a common difference $d = -2$, and $a_1 + a_4 + a_7 + \ldots + a_{97} = 50$, find the value of $a_3 + a_6 + a_9 + \ldots + a_{99}$.
-82
75.78125
22,963
Given the sequence $\{a_n\}$ with the general term formula $a_n = -n^2 + 12n - 32$, determine the maximum value of $S_n - S_m$ for any $m, n \in \mathbb{N^*}$ and $m < n$.
10
21.09375
22,964
Given the function $f(x)=\cos(\frac{1}{2}x-\frac{π}{3})$, the graph is shifted to the right by $φ(0<φ<\frac{π}{2})$ units to obtain the graph of the function $g(x)$, and $g(x)+g(-x)=0$. Determine the value of $g(2φ+\frac{π}{6})$.
\frac{\sqrt{6}+\sqrt{2}}{4}
22.65625
22,965
Given $S$ is the set of the 1000 smallest positive multiples of $5$, and $T$ is the set of the 1000 smallest positive multiples of $9$, determine the number of elements common to both sets $S$ and $T$.
111
89.84375
22,966
If $\sec y + \tan y = 3,$ then find $\sec y - \tan y.$
\frac{1}{3}
97.65625
22,967
How many times does the digit 9 appear in the list of all integers from 1 to 1000?
300
99.21875
22,968
Given the function $f(x)= \sqrt {2}\cos (x+ \frac {\pi}{4})$, after translating the graph of $f(x)$ by the vector $\overrightarrow{v}=(m,0)(m > 0)$, the resulting graph exactly matches the function $y=f′(x)$. The minimum value of $m$ is \_\_\_\_\_\_.
\frac {3\pi}{2}
21.09375
22,969
Circle $\Gamma$ has diameter $\overline{AB}$ with $AB = 6$ . Point $C$ is constructed on line $AB$ so that $AB = BC$ and $A \neq C$ . Let $D$ be on $\Gamma$ so that $\overleftrightarrow{CD}$ is tangent to $\Gamma$ . Compute the distance from line $\overleftrightarrow{AD}$ to the circumcenter of $\triangle ADC$ . *Proposed by Justin Hsieh*
4\sqrt{3}
7.8125
22,970
Let $ a,b,c,d$ be rational numbers with $ a>0$ . If for every integer $ n\ge 0$ , the number $ an^{3} \plus{}bn^{2} \plus{}cn\plus{}d$ is also integer, then the minimal value of $ a$ will be
$\frac{1}{6}$
0
22,971
Three cars start simultaneously from City A, heading towards City B along the same highway. The second car travels 4 kilometers per hour less than the first car and 6 kilometers per hour more than the third car. The second car arrives at City B 3 minutes later than the first car and 5 minutes earlier than the third car. Assuming they do not stop on the way and their speeds are constant, the distance from City A to City B is     kilometers, and the speed of the second car is     kilometers per hour.
96
25.78125
22,972
An angle can be represented by two uppercase letters on its sides and the vertex letter, such as $\angle A O B$ (where “ $\angle$ " represents an angle), or by $\angle O$ if the vertex has only one angle. In the triangle $\mathrm{ABC}$ shown below, $\angle B A O=\angle C A O, \angle C B O=\angle A B O$, $\angle A C O=\angle B C O$, and $\angle A O C=110^{\circ}$, find $\angle C B O=$ $\qquad$ .
20
36.71875
22,973
Given the sequence $$1, \frac{1}{2}, \frac{2}{1}, \frac{1}{3}, \frac{2}{2}, \frac{3}{1}, \frac{1}{4}, \frac{2}{3}, \frac{3}{2}, \frac{4}{1}, \ldots$$, find the position of $$\frac{8}{9}$$ in this sequence.
128
43.75
22,974
Determine the coefficient of the term containing $x^3$ in the expansion of ${(1+2x)}^{5}$. (The result should be represented as a number.)
80
80.46875
22,975
Given the function $f(x)=e^{x}\cos x-x$. (Ⅰ) Find the equation of the tangent line to the curve $y=f(x)$ at the point $(0,f(0))$; (Ⅱ) Find the maximum and minimum values of the function $f(x)$ in the interval $\left[0, \frac{\pi}{2}\right]$.
-\frac{\pi}{2}
89.0625
22,976
For any interval $\mathcal{A}$ in the real number line not containing zero, define its *reciprocal* to be the set of numbers of the form $\frac 1x$ where $x$ is an element in $\mathcal{A}$ . Compute the number of ordered pairs of positive integers $(m,n)$ with $m< n$ such that the length of the interval $[m,n]$ is $10^{10}$ times the length of its reciprocal. *Proposed by David Altizio*
60
94.53125
22,977
Place four balls numbered 1, 2, 3, and 4 into three boxes labeled A, B, and C. (1) If none of the boxes are empty and ball number 3 must be in box B, how many different arrangements are there? (2) If ball number 1 cannot be in box A and ball number 2 cannot be in box B, how many different arrangements are there?
36
93.75
22,978
Find the sum of all values of $a + b$ , where $(a, b)$ is an ordered pair of positive integers and $a^2+\sqrt{2017-b^2}$ is a perfect square.
67
68.75
22,979
Given a circle $C: (x-1)^{2} + (y-2)^{2} = 25$ and a line $l: mx-y-3m+1=0$ intersect at points $A$ and $B$. Find the minimum value of $|AB|$.
4\sqrt{5}
41.40625
22,980
The ancient Chinese mathematical classic "The Nine Chapters on the Mathematical Art" contains a problem called "Rice and Grain Separation". During the collection of grain in a granary, 1524 "shi" (a unit of weight) of rice was received, but it was found to contain grains of another type mixed in. A sample of rice was taken and it was found that out of 254 grains, 28 were not rice. Approximately how much of this batch of rice is not rice?
168
96.09375
22,981
Let $x$ and $y$ be positive real numbers. Find the minimum value of \[x^2 + y^2 + \frac{4}{(x + y)^2}.\]
2\sqrt{2}
63.28125
22,982
A $20$-quart radiator initially contains a mixture of $18$ quarts of water and $2$ quarts of antifreeze. Six quarts of the mixture are removed and replaced with pure antifreeze liquid. This process is repeated three more times. Calculate the fractional part of the final mixture that is water. **A)** $\frac{10.512}{20}$ **B)** $\frac{1}{3}$ **C)** $\frac{7.42}{20}$ **D)** $\frac{4.322}{20}$ **E)** $\frac{10}{20}$
\frac{4.322}{20}
57.03125
22,983
Given the function $f(x)=e^{x}-ax-1$ ($a$ is a real number), and $g(x)=\ln x-x$. (I) Discuss the monotonic intervals of the function $f(x)$. (II) Find the extreme values of the function $g(x)$.
-1
52.34375
22,984
Given the parabola $y^2 = 4x$ whose directrix intersects the x-axis at point $P$, draw line $l$ through point $P$ with the slope $k (k > 0)$, intersecting the parabola at points $A$ and $B$. Let $F$ be the focus of the parabola. If $|FB| = 2|FA|$, then calculate the length of segment $AB$.
\frac{\sqrt{17}}{2}
12.5
22,985
Let \( f: \mathbb{N}^{*} \rightarrow \mathbb{N}^{*} \) be a function that satisfies the following conditions: 1. \( f(1)=1 \) 2. \( f(2n)=f(n) \) 3. \( f(2n+1)=f(n)+1 \) What is the greatest value of \( f(n) \) for \( 1 \leqslant n \leqslant 2018 \) ?
10
100
22,986
$(1)$ Calculate: $2^{-1}+|\sqrt{6}-3|+2\sqrt{3}\sin 45^{\circ}-\left(-2\right)^{2023}\cdot (\frac{1}{2})^{2023}$. $(2)$ Simplify and then evaluate: $\left(\frac{3}{a+1}-a+1\right) \div \frac{{{a}^{2}}-4}{{{a}^{2}}+2a+1}$, where $a$ takes a suitable value from $-1$, $2$, $3$ for evaluation.
-4
62.5
22,987
Given that the focus of the parabola $C: y^{2}=4x$ is $F$, two lines $l_{1}$ and $l_{2}$ are drawn passing through point $F$. Line $l_{1}$ intersects the parabola $C$ at points $A$ and $B$, while line $l_{2}$ intersects the parabola $C$ at points $M$ and $N$. If the product of the slopes of $l_{1}$ and $l_{2}$ is $-1$, calculate the minimum value of $|AB|+|MN|$.
16
95.3125
22,988
If $\theta \in (0^\circ, 360^\circ)$ and the terminal side of angle $\theta$ is symmetric to the terminal side of the $660^\circ$ angle with respect to the x-axis, and point $P(x, y)$ is on the terminal side of angle $\theta$ (not the origin), find the value of $$\frac {xy}{x^{2}+y^{2}}.$$
\frac {\sqrt {3}}{4}
0
22,989
Alexio now has 150 cards numbered from 1 to 150, inclusive, and places them in a box. He chooses a card at random. What is the probability that the number on the card he picks is a multiple of 4, 5 or 6? Express your answer as a reduced fraction.
\frac{7}{15}
28.90625
22,990
In $\triangle ABC$, $\sin (C-A)=1$, $\sin B= \frac{1}{3}$. (I) Find the value of $\sin A$; (II) Given $b= \sqrt{6}$, find the area of $\triangle ABC$.
3\sqrt{2}
46.875
22,991
Given that $A$, $B$, $C$ are the three internal angles of $\triangle ABC$, and their respective opposite sides are $a$, $b$, $c$, and $2\cos ^{2} \frac {A}{2}+\cos A=0$. (1) Find the value of angle $A$; (2) If $a=2 \sqrt {3},b+c=4$, find the area of $\triangle ABC$.
\sqrt {3}
0
22,992
Determine the value of the infinite product $(3^{1/4})(9^{1/16})(27^{1/64})(81^{1/256}) \dotsm$ plus 2, the result in the form of "$\sqrt[a]{b}$ plus $c$".
\sqrt[9]{81} + 2
49.21875
22,993
On an east-west shipping lane are ten ships sailing individually. The first five from the west are sailing eastwards while the other five ships are sailing westwards. They sail at the same constant speed at all times. Whenever two ships meet, each turns around and sails in the opposite direction. When all ships have returned to port, how many meetings of two ships have taken place?
25
88.28125
22,994
Given \(0 \le x_0 < 1\), let \[x_n = \left\{ \begin{array}{ll} 3x_{n-1} & \text{if } 3x_{n-1} < 1 \\ 3x_{n-1} - 1 & \text{if } 1 \le 3x_{n-1} < 2 \\ 3x_{n-1} - 2 & \text{if } 3x_{n-1} \ge 2 \end{array}\right.\] for all integers \(n > 0\), determine the number of values of \(x_0\) for which \(x_0 = x_6\).
729
42.1875
22,995
Let \( a, b, c \) be real numbers such that \( 9a^2 + 4b^2 + 25c^2 = 1 \). Find the maximum value of \[ 3a + 4b + 5c. \]
\sqrt{6}
62.5
22,996
Given the function f(x) = $\frac{1}{3}$x^3^ + $\frac{1−a}{2}$x^2^ - ax - a, x ∈ R, where a > 0. (1) Find the monotonic intervals of the function f(x); (2) If the function f(x) has exactly two zeros in the interval (-3, 0), find the range of values for a; (3) When a = 1, let the maximum value of the function f(x) on the interval [t, t+3] be M(t), and the minimum value be m(t). Define g(t) = M(t) - m(t), find the minimum value of the function g(t) on the interval [-4, -1].
\frac{4}{3}
5.46875
22,997
Given a complex number $z$ that satisfies the following two conditions: ① $1 < z + \frac{2}{z} \leqslant 4$. ② The real part and the imaginary part of $z$ are both integers, and the corresponding point in the complex plane is located in the fourth quadrant. (I) Find the complex number $z$; (II) Calculate $|\overline{z} + \frac{2 - i}{2 + i}|$.
\frac{\sqrt{65}}{5}
78.125
22,998
Find the smallest composite number that has no prime factors less than 20.
667
9.375
22,999
How many paths are there from point $C$ to point $D$ on a grid, if every step must be either to the right or upwards, and the grid dimensions are now 7 steps to the right and 9 steps upward?
11440
100