1- Choice B is correct
The correct answer is Quantity B is greater. (x + y)2=(x + y) (x + y)=x2 + 2 x y + y2→Since y2>0→x2 + 2 x y + y2>x2 + 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=23 x + 12→0=23 p + 12 Solve for p in the equation. 0=23 p + 12→23 p=− 12→p=(− 12) × (32)=− 18 (0,q):y=23 x + 12→q=23 (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 √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. x2 − 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=interest amountloan × 100→p=52515000 × 100=3.5
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7- Choice C is correct
The correct answer is 3 x + 2 Since, 81=34 Then: (36x) (81)=32y→(36x) (34)=32y Use exponent “product rule”: x^n×x^m=x^(n+m) (36x) (34)=32y→36x+4=32y 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√3 cm2 Area of the triangle is: 12 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° × √3 CD =4, then AD =4 × √3 Area of the triangle ABC is: 12 AD×BC =12 4√3 × 8=16√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) =sum of termsnumber of terms⇒88=sum of terms50⇒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 𝑛^2\ +\ 2\ (𝑛\ −\ 1) , 5 \ n , 6\ (𝑛\ +\ 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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