1- Choice B is correct
The correct answer is 4 Simplify:2(x + 3) = 4(x − 6) + 22 ⇒ 2x +6=4x − 24 + 22 ⇒ 2x + 6 = 4x – 2 Subtract 2x from both sides:6 = 2x – 2, Add 2 to both sides:8 = 2x ⇒ 4 = x
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2- Choice E is correct
The corret answer is 275 Add the first 5 numbers. 20 + 25 + 15 + 30 + 35=125 To find the distance traveled in the next 5 hours, multiply the average by number of hours. Distance = Average × Rate =30 × 5=150, Add both numbers. 125 + 150=275
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3- Choice A is correct
The correct answer is 125 x=100 + 25=125
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4- Choice C is correct
The correct answer is 5 Use Pythagorean Theorem: a2 + b2 = c2 ⇒ 42 + 32 = c2 ⇒ 25=c2⇒c=5
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5- Choice A is correct
The correct answer is 6 x2 + 19 x y + 10 y2 Use FOIL (First, Out, In, Last)(3x + 2y) (2x + 5y) = 6x2 + 15xy + 4xy + 10y2 = 6x2 + 19xy + 10y2
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6- Choice D is correct
The correct answer is 150 Use percent formula:part =percent100×whole 45=percent100 × 30⇒45=percent × 30100⇒45=percent× 310, multiply both sides by 10. 450=percent × 3, divide both sides by 3 ⇒ 150= percent
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7- Choice B is correct
The correct answer is 108% To find the discount, multiply the number by (100% – rate of discount). Therefore, for the first discount we get: (D) (100% – 10%)= (D) (0.90)=0.90 D For increase of 20%:(0.90D) (100% + 20%)=(0.90D) (1.20)=1.08D=108% of D
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8- Choice A is correct
The correct answer is 2 y=3 a b − 4 b2 Plug in the values of a and b in the equation: a=3 and b=2 y=3 (3) (2) − 4 (2)2=18 − 4 (4)=18 − 16=2
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9- Choice E is correct
The correct answer is 72 4.5% of 1,600=0.045 × 1600=72
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10- Choice B is correct
The correct answer is 7 The percent of girls playing tennis is: 35%×20%=0.35 × 0.20=0.07=7%
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11- Choice C is correct
The correct answer is 22 hours and 20 minutes Use distance formula: Distance = Rate × time ⇒ 670=30×T, divide both sides by 30 ⇒ 67030=T ⇒ T=22.33 hours. Change hours to minutes for the decimal part. 0.33 hours =0.33 × 60=20
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12- Choice A is correct
The correct answer is 24% Use the formula for Percent of Change: New Value − Old ValueOld Value × 100% 38 − 5050 × 100%=– 24% (negative sign here means that the new price is less than old price).
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13- Choice A is correct
The correct answer is 204 π in2 Surface Area of a cylinder =2 π r (r + h), The radius of the cylinder is 6 inches and its height is 11 inches. Surface Area of a cylinder =2 (π) (6) (6 + 11)=204 π
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14- Choice C is correct
The correct answer is 9 Let x be the number. Write the equation and solve for x. 12 × 12 = 23 x ⇒ 1 × 122=2 x3 use cross multiplication to solve for x. 12 × 3 = 2x × 2 ⇒ 36 = 4x ⇒ x = 9
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15- Choice D is correct
The correct answer is 15 x y + 6 x Use distributive property: 3x(2 + 5y) = 6x + 15xy = 15xy + 6x
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16- Choice B is correct
The correct answer is 8 The diagonal of the square is 4. Let x be the side. Use Pythagorean Theorem: a2 + b2=c2 x2 + x2 = 42 ⇒ 2x2 = 42 ⇒ 2x2 = 16 ⇒ x2 = 8 ⇒ x= √8 The area of the square is: √8×√8 = 8
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17- Choice D is correct
The correct answer is $1000 Use simple interest formula: (I = interest, p = principal, r = rate, t = time) I = (1000)×(0.025)×(4)=1000
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18- Choice E is correct
The correct answer is 75 cm3 The formula of the volume of pyramid is: V =l × w × h3 The length and width of the pyramid are 5 cm and its height is 9 cm. Therefore: V =5 × 5 × 93=75cm3
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19- Choice A is correct
The correct answer is $500 Let x be the original price. If the price of a laptop is decreased by 20% to $400, then: 80% of x = 400 ⇒ 0.80x = 400 ⇒ x = 400 ÷ 0.80 = 500
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20- Choice D is correct
The correct answer is 600 ml 6% of the volume of the solution is alcohol. Let x be the volume of the solution. Then: 6% of x = 36 ml ⇒ 0.06x = 36 ⇒ x = 36÷0.06 = 600
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21- Choice C is correct
The correct answer is 2 Solving Systems of Equations by Elimination 2 x − 3 y=− 22 − x + 4 y=16 Multiply the second equation by 2, then add it to the first equation. 2 x − 3 y=− 22 2(− x + 4 y=16)⇒ −2 x + 8 y=32 ⇒ 5 y=10 ⇒ y=2
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22- Choice B is correct
The correct answer is 72 The perimeter of the trapezoid is 40. So, the missing side (height) is =40 – 14 – 8 – 10=8 Area of the trapezoid: A =12 h (b1 + b2)=12(8) (10 + 8)=72
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23- Choice C is correct
The correct answer is 300 The ratio of boys to girls is 3:4. Therefore, there are 3 boys out of 7 students. To find the answer, first, divide the total number of students by 7, then multiply the result by 3. 700 ÷ 7=100⇒100×3=300
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24- Choice E is correct
The correct answer is 8 Write the numbers in order: 3 , 4 , 5 , 8 , 11 , 15 , 16 Since we have 7 numbers (7 is odd), then the median is the number in the middle, which is 8.
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25- Choice A is correct
The correct answer is 32 average =sum of termsnumber of terms⇒16=10 + 14 + 8 + x4⇒64=32 + x⇒x=32
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26- Choice E is correct
The correct answer is $ 450 Use simple interest formula: (I = interest, p = principal, r = rate, t = time) I=(6,000) (0.025) (3)=450
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27- Choice B is correct
The correct answer is 720 Let x be the original price. If the price of the bed is decreased by 25% to $ 540, then: 75% of x=540⇒0.75 x=540⇒x=540 ÷ 0.75=720
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28- Choice C is correct
The correct answer is 14 π Use the formula of areas of circles. Area =π r2⇒49 π=π r2⇒49=r2⇒r=7 Radius of the circle is 7. Now, use the circumference formula: Circumference =2 π r=2 π(7)=14 π
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29- Choice C is correct
The correct answer is 137 The question is this:1.85 is what percent of 1.35? Use percent formula:part =percent100 × whole 1.85=percent100 × 1.35⇒1.85=percent × 1.35100⇒185=percent × 1.35 ⇒ percent=1851.35=137
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30- Choice D is correct
The correct answer is 0 , − 2 , − 1 First factor the function:x (x + 2) (x + 1) To find the zeros, f(x) should be zero.f(x)=x (x + 2) (x + 1)=0 Therefore, the zeros are:x=0, (x + 2)=0⇒x=− 2 , (x + 1)=0⇒x=− 1
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31- Choice A is correct
The correct answer is I>15000 x + 20000 Let x be the number of years. Therefore, $ 15,000 per year equals 15000 x. starting from $ 20,000 annual salary means you should add that amount to 15000 x. Income more than that is:I>15000 x + 20000
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32- Choice E is correct
The correct answer is 35 Some of prime numbers are: 2 , 3 , 5 , 7 , 11 , 13 Find the product of two consecutive prime numbers: 2 × 3=6 (not in the options) 3 × 5=15(not in the options), 5 × 7=35 (bingo!)
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33- Choice C is correct
The correct answer is 18 If the score of Jennifer was 72, therefore the score of Kevin is 36. Since the score of Amy was half that of Kevin, therefore, the score of Amy is 18.
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34- Choice A is correct
The correct answer is 52 Let x be the smallest number. Then, these are the numbers: x , x + 1 , x + 2 , x + 3 , x + 4 average =sum of termsnumber of terms⇒54=x + (x + 1) + (x + 2) + (x + 3) + (x + 4)5⇒ 54=5 x + 105⇒270=5 x + 10⇒260=5 x⇒x=52
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35- Choice E is correct
The correct answer is 50 feet The relationship among all sides of a special right triangle 30^° \ - \ 60^° \ - \ 90^° is provided in this triangle: In this triangle, the opposite side of the 30^° angle is half of the hypotenuse. Draw the shape of this question: The latter is the hypotenuse. Therefore, the ladder is 50 ft.
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36- Choice A is correct
The correct answer is 400\% Write the equation and solve for B:0.40 A = 0.10 B, divide both sides by 0.10 , then you will have \frac{0.40}{0.10} A = B, therefore: B = 4 A, and B is 4 times of A or it’s 400\% of A.
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37- Choice E is correct
The correct answer is 7 Let x be the number. Write the equation and solve for x. (35 \ – \ x) \ ÷ \ x= 4 Multiply both sides by x. (35 \ – \ x) = 4 \ x, then add x both sides. 35 = 5 \ x, now divide both sides by 5 ⇒ x = 7
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38- Choice E is correct
The correct answer is 40 To find the number of possible outfit combinations, multiply the number of options for each factor: 4 \ × \ 5 \ × \ 2 =40
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39- Choice D is correct
The correct answer is 36 The sum of supplement angles is 180. Let x be that angle. Therefore, x = \frac{1}{4}(180 \ - \ x) ⇒ x \ + \ 4 \ x = 180 ⇒ 5x \ = \ 180 , divide both sides by 5 : x = 36
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40- Choice B is correct
The correct answer is 16 The area of the floor is: 4 \ cm \ × \ 28 \ cm = 112 cm, The number is tiles needed = 112 \ ÷ \ 7 = 16
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41- Choice D is correct
The correct answer is 22.8 ft Use Pythagorean theorem: a^2 \ + \ b^2 = c^2 , 14^2 \ + \ 18^2= x^2 , 196 \ + \ 324 = x^2 520 = x^2 ⇒ x = 22.8
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42- Choice A is correct
The correct answer is 245 cm^3 The formula of the volume of a pyramid is: V=\frac {l \times w \times h}{3} The length and width of the pyramid are 7 cm and its height is 14 cm. Therefore: V = \frac{7 \ \times \ 7 \ \times \ 15}{3} = 245 cm^3
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43- Choice C is correct
The correct answer is $\ 500 Let x be the original price. If the price of a laptop is decreased by 20\% to $\ 400 , then: 80\% of x= 400 \ ⇒ \ 0.80x \ = \ 400 ⇒ x = 400 \ ÷ \ 0.80 \ = \ 500
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44- Choice D is correct
The correct answer is 5.25 The weight of 10.5 meters of this rope is: 10.5 \ × \ 500 \ g = 5250 g 1 kg = 1000 g, therefore, 5250 g ÷ \ 1000 = 5.25 kg
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45- Choice A is correct
The correct answer is 71.2 average = \frac{sum \ of \ terms }{number \ of \ terms} The sum of the weight of all girls is: 24 \ × \ 70 = 1680 kg The sum of the weight of all boys is: 36 \ × \ 72 =2592 kg The sum of the weight of all students is: 1680 \ + \ 2592 =4272 kg average = \frac{4272}{60}= 71.2
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46- Choice D is correct
The correct answer is 2 : 3 The average speed of john is: 240 \ ÷ \ 8 = 30 The average speed of Alice is: 270 \ ÷ \ 6 = 45 Write the ratio and simplify. 30 : 45 ⇒ 2 : 3
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47- Choice D is correct
The correct answer is 1728 cm^3 If the length of the box is 36, then the width of the box is one-third of it, 12, and the height of the box is 4 (one-third of the width). The volume of the box is: V = l \ w \ h = (36) \ (12) \ (4) =1728 cm^3
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48- Choice A is correct
The corrrect answer is 20\% Use this formula: Percent of Change =\frac{New \ Value \ - \ Old \ Value}{Old Value} \ × \ 100\% \frac{16000 \ - \ 20000}{20000} \ × \ 100\% = 20\% and \frac{12800 \ - \ 16000}{16000} \ × \ 100\% = 20\%
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49- Choice A is correct
The correct answer is (2 \ , \ 5) , (1 \ , \ 4) , (- \ 3 \ , \ 7) Since the triangle ABC is reflected over the y-axis, then all values of y’s of the points don’t change and the sign of allx ’s change. (remember that when a point is reflected over the y-axis, the value of y does not change and when a point is reflected over the x-axis, the value of x does not change). Therefore: (− \ 2,5) changes to (2 \ , \ 5) (− \ 1 \ , \ 4) changes to (1 \ , \ 4) (3 \ , \ 7) changes to (− \ 3 \ , \ 7)
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50- Choice C is correct
The correct answer is 6.3 \ × \ 10^1 (4.2 \ × \ 10^5) \ × \ (1.5 \ × \ 10^{−4}) = (4.2 \ × \ 1.5) \ × \ (10^5 \ × \ 10^{−4}) = 6.3 \ × \ (10^{5 + (−4)} ) = 6.3 \ × \ 10^1
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