1- Choice B is correct
The correct answer is Quantity B is greater. \((x\ +\ y)^2=(x\ +\ y)\ (x\ +\ y)=x^2\ +\ 2\ x\ y\ +\ \ y^2 →\)Since \(y^2>0→x^2\ +\ 2\ x\ y\ +\ y^2> x^2\ +\ 2\ x\ y\)
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2- Choice B is correct
The correct answer is Quantity B is greater. Solve for \(p\) and \(q\) in the equation. \((p,0): y=\frac{2}{3} \ x\ +\ 12→0=\frac{2}{3} \ p\ +\ 12\) Solve for \(p\) in the equation. \(0=\frac{2}{3} \ p\ +\ 12→\frac{2}{3}\ p=-\ 12→p=(-\ 12)\ ×\ (\frac{3}{2})=-\ 18\) \((0,q): y=\frac{2}{3} \ x\ +\ 12→q=\frac{2}{3} \ (0)\ +\ 12→q=12\) \(q>p\)
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3- Choice B is correct
The correct answer is Quantity B is greater. Since, \(x\) is a positive integer greater than \(1\), then the minimum value of \(\sqrt{x}\) is greater than \(1\).
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4- Choice B is correct
The correct answer is Quantity B is greater. Use factoring method to solve for x in the equation. \(x^2\ -\ 2\ x\ -\ 15=0→(x\ -\ 5)\ (x\ +\ 3)=0\) Then: \((x\ -\ 5)=0→x=5\) Or \((x\ +\ 3)=0→x=-\ 3\) Both values of \(x\) are less than \(6\). So, quantity B is greater
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5- Choice D is correct
The correct answer is The relationship cannot be determined from the information given. Let’s choose some values for \(x\) and \(y\). \(x=1 ,\ y=0.5→(A=1.5)>(B=0.5)\) and if \(x=1\) and \(y=-\ 0.5 →B>A\)
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6- Choice B is correct
The correct answer is \(3.5\) The loan is \($15,000\) and its interest is \($1,050\). Since the interest is for \(2\) years. Therefore, the simple interest rate \((p)\) per year is \($525\). Then: interest rate\(=\frac{interest\ amount}{loan}\ ×\ 100→p=\frac{525}{15000}\ ×\ 100=3.5\)
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7- Choice C is correct
The correct answer is \(3 \ x\ + \ 2\) Since, \(81=3^4\) Then: \((3^{6x} )\ (81)=3^{2y}→(3^{6x} )\ (3^4 )=3^{2y}\) Use exponent “product rule”: x^n×x^m=x^(n+m) \((3^{6x} )\ (3^4 )=3^{2y}→3^{6x+4}=3^{2y}\) The bases are the same. Therefore, the powers must be equal. \(6\ x\ +\ 4=2\ y\) Divide both sides of the equation by \(2\): \(6\ x\ +\ 4=2\ y →3\ x\ +\ 2=y\)
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8- Choice E is correct
The correct answer is \(240\) The ratio of boy to girls is \(2:3\). Therefore, there are 2 boys out of \(5\) students. To find the answer, first divide the total number of students by \(5\), then multiply the result by \(2\). \(600 \ ÷\ 5 = 120 ⇒ 120 \ ×\ 2 = 240\)
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9- Choice A is correct
The correct answer is \(16\sqrt{3}\) cm\(^2\) Area of the triangle is: \(\frac{1}{2}\) AD \(×\)BC and AD is perpendicular to BC. Triangle ADC is a \(30^°-60^°- 90^°\) right triangle. The relationship among all sides of right triangle \(30^°-60^°- 90^°\) is provided in the following triangle: In this triangle, the opposite side of \(30^°\) angle is half of the hypotenuse. And the opposite side of \(60^°\) is opposite of \(30^° \ ×\ \sqrt{3}\) CD \(= 4\), then AD \(= 4 \ ×\ \sqrt{3}\) Area of the triangle ABC is: \(\frac{1}{2}\) AD\(×\)BC \(= \frac{1}{2 }\ 4\sqrt{3}\ ×\ 8=16\sqrt{3}\)
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10- Choice E is correct
The correct answer is \(225\) \(0.6\ x=(0.3)\ ×\ 20→x=10→(x+5)^2=(15)^2=225\)
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11- Choice D is correct
The correct answer is \(60\) feet The relationship among all sides of special right triangle \(30^°\ -\ 60^°\ -\ 90^°\) is provided in this triangle: In this triangle, the opposite side of \(30^°\) angle is half of the hypotenuse. Draw the shape of this question: The latter is the hypotenuse. Therefore, the latter is \(60\) ft.
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12- Choice C is correct
The correct answer is \(87.5\) The difference of \(94\) and \(69\) is \(25\). average (mean) \(= \frac{sum \ of \ terms }{number\ of\ terms} ⇒ 88 = \frac{sum \ of \ terms }{50} ⇒ sum = 88 \ ×\ 50 = 4400\) Therefore, \(25\) should be subtracted from the sum. \(4400 \ –\ 25 = 4375\), mean \(= \frac{sum \ of\ terms }{number \ of\ terms} ⇒\) mean \(= \frac{4375 }{50} = 87.5\)
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13- Choice D is correct
The correct answer is \(\frac{1}{2}\) To get a sum of \(6\) or \(9\) for two dice, we should get \(3\) and \(3\), or \(3\) and \(6\), or \(6\) and \(3\). Therefore, there are \(3\) options. Since, we have \(6 \ ×\ 6 = 36\) total options, the probability of getting a sum of \(6\) and \(9\) is \(3\) out of \(36\) or \(\frac{1}{12}\).
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14- Choice A is correct
The correct answer is \(10\) meters The width of the rectangle is twice its length. Let \(x\) be the length. Then, width \(=2\ x\) Perimeter of the rectangle is \(2\) (width \(+\) length) \(= 2\ (2\ x\ +\ x)=60 ⇒ 6\ x=60 ⇒ x=10\) Length of the rectangle is \(10\) meters.
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15- Choice C is correct
The correct answer is \(a=c\) Let’s find the mean (average), mode and median of the number of cities for each type of pollution. number of cities for each type of pollution: \(6, \ 3, \ 4, \ 9, \ 8\) average (mean) \(=\frac{ sum \ of \ terms }{number \ of\ terms}⇒\)average\(=\frac{6\ +\ 3\ +\ 4\ +\ 9\ +\ 8}{5}=\frac{30}{5}=6\) Median is the number in the middle. To find median, first list numbers in order from smallest to largest. \(3, \ 4, \ 6, \ 8, \ 9\) Median of the data is \(6\). Mode is the number which appears most often in a set of numbers. Therefore, there is no mode in the set of numbers. Median \(=\) Mean, then, \(a=c\)
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16- Choice A is correct
The correct answer is \(60\% , 40\% , 90\%\) percent of cities are in the type of pollution A : \(\frac{6}{10} \ ×\ 100= 60\%\) percent of cities are in the type of pollution C : \(\frac{4}{10}\ ×\ 100= 40\%\) percent of cities are in the type of pollution E : \(\frac{9}{10}\ ×\ 100= 90\%\)
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17- Choice D is correct
The correct answer is \(y\ +\ 4\ x=Z\) \(x\) and \(Z\) are colinear. \(y\) and \(5\ x\) are colinear. Therefore, \(x\ +\ Z=y\ +\ 5\ x\), subtract x from bh sides,then, \(Z=y\ +\ 4\ x\)
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18- Choice D is correct
The correct answer is \(16\) average = \(\frac{\ sum\ \ of\ \ terms}{\ number\ \ of\ \ terms} ⇒\) (average of \(6\) numbers) \(12 = \frac{\ sum\ \ of\ \ numbers}{6} ⇒\) sum of \(6\) numbers is \(12 \ ×\ 6 = 72\) (average of \(4\) numbers) \(10 = \frac{\ sum\ \ of\ \ numbers }{4} ⇒\)sum of \(4\) numbers is \(10 \ ×\ 4 = 40\) sum of \(6\) numbers \(–\) sum of \(4\) numbers \(=\) sum of \(2\) numbers \(72 \ –\ 40 = 32\) average of \(2\) numbers \(=\frac {32 }{2}=16\)
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19- Choice C is correct
The correct answer is \(-\ 2 \) Solving Systems of Equations by Elimination Multiply the first equation by \(- \ 2\), then add it to the second equation. \(\cfrac{\begin{align} - \ 2 \ (2 \ x \ + \ 5 \ y \ = \ 11 \\ 4 \ x \ - \ 2 \ y \ = - \ 14 \end{align}}{} \) \(\cfrac{ \begin{align} - \ 4 \ x \ - \ 10 \ y \ = \ - \ 22 \\ 4 \ x \ - \ 2 \ y \ = - \ 14 \end{align} }{\begin{align} - \ 12\ y \ = - \ 36 \\ ⇒ y \ = \ 3 \end{align}} \) Plug in the value of y into one of the equations and solve for \(x\). \(2 \ x \ + \ 5 \ (3)= 11 ⇒\) \(2 \ x \ + \ 15= 11 ⇒\) \(2 \ x= \ - \ 4 ⇒ x= \ - \ 2\)
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20- Choice D is correct
The correct answer is \(5\ x\ +\ 5\) Five years ago, Amy was x times as old as Mike. Mike is \(10\) years now. Therefore, \(5\) years ago Mike was \(5\) years old. Five years ago, Amy was: A\(=5\ ×\ x=5\ x\) Now Amy is: A\(=5\ x\ +\ 5\)
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20- Choice D is correct
The correct answer is \(5\ x\ +\ 5\) Five years ago, Amy was x times as old as Mike. Mike is \(10\) years now. Therefore, \(5\) years ago Mike was \(5\) years old. Five years ago, Amy was: A\(=5\ ×\ x=5\ x\) Now Amy is: A\(=5\ x\ +\ 5\)
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21- Choice A is correct
The correct answer is Quantity A is greater. \(\frac{x\ +\ 5}{5}=\frac{x}{5}\ +\ 1\) \(\frac{x^2\ -\ 36}{x^2\ -\ 6\ x}=\frac{(x\ -\ 6)\ (x\ +\ 6)}{(x\ (x\ -\ 6))}=\frac{(x\ +\ 6)}{x}=\frac{1\ +\ 6}{x}\) Since,\(\frac{x}{5}>\frac{6}{x}\) for the values of \(6<\ x\ <9 →\) Quantity A \(>\) Quantity B
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22- Choice C is correct
The correct answer is The two quantities are equal. Use exponent “product rule”: \(x^n\ ×\ x^m=x^{n+m}\) Quantity A: \((1.888)^4 (1.888)^8=(1.888)^{4+8}=(1.888)^{12}\) Quantity B: \((1.88)^{12}\) The two quantities are equal.
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23- Choice C is correct
The correct answer is The two quantities are equal. Area of a circle \(= π\ r^2→100=π\ r^2→r^2=\frac{100}{π}→r=\frac{10}{\sqrtπ}\)
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24- Choice D is correct
The correct answer is the relationship cannot be determined from the information given Choose different values for \(x\) and find the value of quantity A and quantity B. \(x=1\), then: Quantity A: \( x^{10}=1^{10}=1\) Quantity B: \(x^{20}=1^{20}=1\) The two quantities are equal. \(x=2\), then: Quantity A: \(x^{10}=2^{10}\) Quantity B: \(x^{20}=2^{20}\) Quantity B is greater. Therefore, the relationship cannot be determined from the information given.
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25- Choice A is correct
The correct answer is the Quantity A is greater. Volume of a right cylinder \(= π\ r^2 \ h\to 50\ π=π\ r^2\ h=π\ (2)^2 \ h\to h=12.5\) The height of the cylinder is \(12.5\) inches which is bigger than \(10\) inches.
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26- Choice D is correct
The correct answer is \(\frac{22}{3}\) Set A: {\(3, \ 5, \ 8, \ 10, \ x, \ y\)} Set B: {\(4, \ 6, \ x, \ y\)} The average of the \(4\) numbers in Set B is \(7\). Therefore: \(\frac{4\ +\ 6\ +\ x\ += y}{4}=7\), multiply both sides of the equation by \(4. →10\ +\ x\ +\ y=28→x\ +\ y=18\) Let’s find the average of the \(6\) numbers in Set A when the sum of \(x\) and \(y\) is \(18\). \(\frac{3\ +\ 5\ +\ 8\ +\ 10\ +\ x\ +\ y}{6}=\frac{26\ +\ (x\ +\ y)}{6}=\frac{26\ +\ 18}{6}=\frac{44}{6}=\frac{22}{3}\)
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27- Choice C is correct
The correct answer is \(27\) average \(= \frac{\ sum\ \ of\ \ terms}{\ number\ \ of\ \ terms} ⇒24 = \frac{\ sum\ \ of\ 5 \ numbers}{5} ⇒\) sum of \(5\) numbers is \(24 \ ×\ 5 = 120\) The sum of \(5\) numbers is \(120\). If a sixth number \(42\) is added, then the sum of \(6\) numbers is \(120 \ +\ 42 = 162\) average \(= \frac{\ sum\ \ of\ \ terms}{\ number\ \ of\ \ terms}=\frac {162 }{6}=27\)
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28- Choice D is correct
The correct answer is \(0, 2, 3\) Method 1: Plugin the options and check. A. \( 0\) \((0^2\ +\ 0)\ (0\ -\ 6)=-\ 12\ (0)→0=0!\) It works! B. \(0, 3\ -\ \sqrt{3}, \sqrt{3}\ +\ 3\) \(((3\ -\ \sqrt{3})^2\ +\ (\sqrt{3}\ -\ 3))\ (\sqrt{3}\ -\ 3\ -\ 6)=-\ 12\ (\sqrt{3}\ -\ 3)→ (12\ -\ \sqrt{3})\ (\sqrt{3}\ -\ 9)=-\ 12\sqrt{3}\ +\ 36\) \(21\sqrt{3}\ -\ 99≠-\ 12\sqrt{3}\ +\ 36\), not a solution! C. \(0, -2, -3\) \(((-\ 2)^2\ -\ 2)\ (-\ 2\ -\ 6)=-\ 12\ (-\ 2)→-16≠24!\) not a solution! D \(0, 2, 3\) \((2)^2\ +\ 2)\ (2-6)=-\ 12\ (2)→-\ 24=-\ 24!\), Bingo! E. No solution \(((3)^2\ +\ 2)\ (3\ -\ 6)=-\ 12\ (3)→-\ 36=-\ 36!\), Bingo! Method 2: Solve for \(x\). \((x^2\ +\ x)\ (x\ -\ 6)=-\ 12\ x→x^3\ -\ 5\ x^2\ -\ 6\ x=-\ 12\ x→x(x^2\ -\ 5\ x\ +\ 6)=0 →x\ (x\ -\ 2)\ (x\ -\ 3)=0→x=0\) or \(x=2\) or \(x=3\)
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29- Choice B is correct
The correct answer is \(0.49\) \(a=b-0.3\ b=0.7\ b→\frac{a}{b}=\frac{0.7\ b}{b}=0.7→(\frac{a}{b})^2=(0.7)^2=0.49\)
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30- Choice C is correct
The correct answer is \(38\%\) The population is increased by \(15\%\) and \(20\%\). \(15\%\) increase changes the population to \(115\%\) of original population. For the second increase, multiply the result by \(120\%\). \((1.15)\ ×\ (1.20)=1.38=138\%\) \(38\) percent of the population is increased after two years.
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31- Choice C is correct
The correct answer is \(\frac{2}{5}\) Since the outcomes are mutually exclusive. Then, the sum of probabilities of all outcomes equals to \(1\). Therefore: \(n\ +\ \frac{n}{2}\ +\ \frac{3\ n}{4}\ +\ \frac{n}{4}=1\) Find a common denominator and solve for \(n\). \(n\ +\ \frac{n}{2}\ +\ \frac{3\ n\ }{4} \ +\ \frac{n}{4}=1→\frac{4\ n}{4}\ +\ \frac{2\ n}{4}\ +\ \frac{3\ n}{4} \ +\ \frac{n}{4}=1→\frac{10\ n}{4}=1→10\ n=4→n=\frac{4}{10}=\frac{2}{5}\)
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32- Choice D is correct
The correct answer is \(y\ +\ 4\ x=Z\) \(x\) and \(Z\) are colinear. \(y\) and \(5\ x\) are colinear. Therefore, \(x\ +\ Z=y\ +\ 5\ x\), subtract x from bh sides,then, \(Z=y\ +\ 4\ x\)
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33- Choice B is correct
The correct answer is \(36\) Let \(x\) be the smallest number. Then, these are the numbers: \(x, x\ +\ 1, x\ +\ 2, x\ +\ 3, x\ +\ 4\) average \(= \frac{sum \ of\ terms }{number \ of\ terms} ⇒ 38 = \frac{(x\ +\ (x\ +\ 1)\ +\ (x\ +\ 2)\ +\ (x\ +\ 3)\ +\ (x\ +\ 4))}{5}⇒ 38=\frac{5\ x\ +\ 10}{5} ⇒ 190 = 5\ x\ +\ 10⇒ 180 = 5\ x ⇒ x=36\)
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34- Choice C is correct
The correct answer is \(600\) ml \(4\%\) of the volume of the solution is alcohol. Let \(x\) be the volume of the solution. Then: \(4\%\) of \(x = 24\) ml \(⇒ 0.04\ x = 24 ⇒ x = 24 \ ÷\ 0.04 = 600\)
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35- Choice B is correct
The correct answer is \(0.97\) ratio of women to men in cityA: \(\frac{570}{600}=0.95\) ratio of women to men in city B: \(\frac{291}{300}=0.97\) ratio of women to men in city C: \(\frac{665}{700}=0.95\) ratio of women to men in city D: \(\frac{528}{550}=0.96\)
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36- Choice D is correct
The correct answer is \(1.05\) Percentage of men in city A \(= \frac{600}{1170}\ ×\ 100=51.28\%\) Percentage of women in city C \(= \frac{665}{1365} \ ×\ 100=48.72\%\) percentage of men in city A to percentage of women in C \(= \frac{51.28}{48.72}=1.05\)
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37- Choice C is correct
The correct answer is \(132\) \(\frac{528\ +\ x}{550}=1.2→528\ +\ x=660→x=132\)
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38- Choice D is correct
The correct answer is \( 13 \ π\) cm The rectangle is inscribed in a circle. Therefore, the diagonal of the rectangle is the diameter of the circle. Use Pythagorean theorem to solve for the diagonal of the rectangle. \(a^2\ +\ b^2=c^2\) \(5^2\ +\ 12^2=c^2→25\ +\ 144=c^2→169=c^2→c=13\) The diameter of the circle is \(13\). Therefore, the circumference of the circle is: \(C=π\ d=π\ ×\ 13=13\ π\)
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39- Choice F is correct
The correct answer is \(π^2\ +\ 2\ (π\ −\ 1)\) , \(5 \ n \) , \(6\ (π\ +\ 3)\) \(n\) is even. Plug in an even number for n and check the options. Let’s choose \(2\) for \(n\). Then: A.\(n\ +\ 13\) \(2 \ +\ 13 = 15\) Odd B.\(n^2\ +\ 2\ (n\ -\ 1)\) \(2^2\ +\ 2 \ (2\ -\ 1)=4\ +\ 2\ (1)=6\) Even C.\(5\ n\) \(5 \ ×\ 2 = 10\) Even D.\(3\ n^2\ +\ 5\ n\) \(3\ (2)^2\ +\ 5\ (2)=3\ ×\ 4\ +\ 10=17\) Odd E.\(n^3\ +\ 3\ n \ - \ 1\) \(2^3\ +\ 3\ (2)\ -\ 1=8\ +\ 6\ -\ 1=13\) Odd F.\(6\ (n\ +\ 3)\) \(6\ (2\ +\ 3)=30\) Even
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40- Choice B is correct
The correct answer is \(80\) miles The speed of car A is \(56\) mph and the speed of car B is \(64\) mph. When both cars drive in a straight line toward each other, the distance between the cars decreases at the rate of \(120\) miles per hour: \(56 \ +\ 64 = 120\) \(40\) minutes is two third of an hour. Therefore, they will be \(80\) miles apart \(40\) minutes before they meet. \(\frac{2}{3}\ ×\ 120=80\)
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