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ACT PRACTICE MATHEMATICS TEST 60 Minutes – 60 Questions 1. 7−3 − 3−7 = ? 4 − −4 → 4 − 4 = 0 → Correct answer is D) 0 The absolute value of a number is always positive. 2. A consultant charges $45 for each hour she works on a consultation, plus a flat $30 consulting fee. How many hours of work are included in a $210 bill for a consultation? Let x represent the number of hours of work → $45 per hour plus $30 fee must equal $210 45 x + 30 = 210 → 45 x = 180 → x = 4 → Correct answer is G) 4 3. Vehicle A averages 14 miles per gallon of gasoline, and Vehicle B averages 36 miles per gallon of gasoline. At these rates, how many more gallons of gasoline does Vehicle A need than Vehicle B to make a 1,008 mile trip? Gallons for Vehicle A → 1, 008 miles ÷ 14 mpg = 72 gallons Gallons for Vehicle B → 1, 008 miles ÷ 36 mpg = 28 gallons Vehicle A ( 72 gallons ) − Vehicle B ( 28 gallons ) = 44 gallons → Correct answer is C) 44 4. t 2 − 59t + 54 − 82t 2 + 60t is equivalent to: t 2 − 59t + 54 − 82t 2 + 60t → 1t 2 − 59t + 54 − 82t 2 + 60t → Add like terms → 1t 2 − 82t 2 − 59t + 60t + 54 = −81t 2 + 1t + 54 → −81t 2 + t + 54 → Correct answer is J) − 81t 2 + t + 54 When you add like terms, you add the coefficients (the numbers in front of the variables) but keep the variable part the same. 5. The figure below is composed of square BCDE and equilateral triangle Δ ABE. The length of CD is 6 inches. What is the perimeter of ABCDE, in inches? A If BCDE is a square, then ED, BC , and EB are all 6 inches. If + ABE is an equilateral triangle, then EB, EA, and BA are all 6 inches. Perimeter of ABCDE = AB + BC + CD + DE + EA = 6 + 6 + 6 + 6 + 6 = 30 inches → Correct answer is C) 30 E B D 6 inches C 6. The expression ( 4z + 3 )( z − 2 ) is equivalent to: Use the FOIL method ( First, Outer, Inner, Last ) to multiply binomials → ( 4 z + 3)( z − 2 ) → 4 z ⋅ z + 4 z ⋅ ( −2 ) + 3 ⋅ z + 3 ⋅ ( −2 ) → 4 z 2 − 8 z + 3z − 6 → Add like terms → 4 z 2 − 5 z − 6 → Correct answer is J) 4 z 2 − 5 z − 6 7. If 40% of a given number is 8, then what is 15% of the given number? Convert 40% to a decimal → 40% = 0.4 → "of" in problem means "multiply" → 40% of a number is 8 → 0.4 ∗ x = 8 → x = 20 What is 15% of this number? → Convert 15% to a decimal → 15% = 0.15 → 15% of 20 → 0.15 ∗ 20 = 3.0 → Correct answer is C) 3.0 is % 8 40 = → = → of 100 x 100 Cross multiply → 40 x = 800 → x = 20 = given number → x 15 = → Cross multiply → 100 x = 300 → x = 3 → Correct answer is C) 3.0 20 100 ALTERNATIVE WAY: Use proportion → 8. The 6 consecutive integers below add up to 447. What is the value of x? x − 2, x − 1, x, x + 1, x + 2, x + 3 Add these six terms together and set equal to 447 → ( x − 2 ) + ( x − 1) + x + ( x + 1) + ( x + 2 ) + ( x + 3) = 447 → Add like terms → 6 x + 3 = 447 → 6 x = 444 → x = 74 → Correct answer is H) 74 9. In the standard (x, y) coordinate plane, point M with coordinates (5, 4) is the midpoint of AB, and B has coordinates (7, 3). What are the coordinates of A? ⎛x +x y +y ⎞ ⎛ x + 7 y1 + 3 ⎞ Midpoint = ⎜ 1 2 , 1 2 ⎟ → ( 5 , 4) = ⎜ 1 , ⎟→ 2 ⎠ 2 ⎠ ⎝ 2 ⎝ 2 x +7 y +3 → 10 = x1 + 7 → 3 = x1 , 4 = 1 → 8 = y1 + 3 → 5 = y1 5= 1 2 2 Correct answer is D) ( 3, 5) ALTERNATIVE EXPLANATION: Midpoint is halfway between A and B → 7+? 3+ ? = 5 → ? = 3, = 4 → ? = 5 → Correct answer is D) ( 3, 5) 2 2 10. Rectangle ABCD has vertices A (4,5), B (0, 2), and C (6, –6). These vertices are graphed below in the standard (x, y) coordinate plane. What are the coordinates of vertex D? There are several ways to do this mathematically, but they all take a lot of time. Here’s the quick and dirty way. From point B to point A, you go 4 units to the right and 3 units up. If you start at point C and go 4 units to the right and 3 units up, you end up at the point (10, –3). 6 A 4 B 2 5 10 -2 The correct answer is F) (10, –3). -4 -6 C -8 11. Daisun owns 2 sportswear stores (X and Y). She stocks 3 brands of T-shirts (A, B, and C) in each store. The matrices below show the numbers of each type of Tshirt in each store and the cost for each type of T-shirt. The value of Daisun’s Tshirt inventory is computed using the costs listed. What is the total value of the T-shirt inventory for Daisun’s 2 stores? A B C X ⎡ 100 200 150 ⎤ Y ⎢⎣ 120 50 100 ⎥⎦ Cost A ⎡ $5 ⎤ B ⎢⎢ $10 ⎥⎥ C ⎢⎣ $15 ⎥⎦ This is intended to be a matrix multiplication problem, but you don’t need to understand matrix multiplication to get the correct answer. In store X, 100 A shirts * $5/shirt + 200 B shirts * $10/shirt + 150 B shirts * $15/shirt = $4750. In store Y, 120 A shirts * $5/shirt + 50 B shirts * $10/shirt + 100 B shirts * $15/shirt = $2600. Total inventory = $4750 + $2600 = $7350 Correct answer is E) $7,350 12. Given the triangle shown below with exterior angles that measure x°, y°, and z° as shown, what is the sum of x, y and z? First, find the third angle of the triangle. The three angles of a triangle add up to 180°. The third angle must equal 180° – 57° – 72° = 51°. y° 72° The x° and the 57° are supplementary, so x° = 180° – 57° = 123°. x° 57° The y° and the 72° are supplementary, so y° = 180° – 72° = 108°. The z° and the 51° are supplementary, so z° = 180° – 51° = 129°. x + y + z = 123° + 108° + 129° = 360° → Correct answer is J) 360° 51° z° ALTERNATE EXPLANATION: The sum of the exterior angles of a convex polygon is always 360°, regardless of the number of sides. Use the following information to answer questions #13 – #15. A poll of 200 registered voters was taken before the election of mayor of Springdale. All 200 voters indicated which 1 of the 4 candidates they would vote for. The results of the poll are given in the table below. Candidate Blackcloud Lue 13) Number of voters 50 80 Candidate Gomez Whitney Number of voters 40 30 What percent of the voters polled chose Whitney in the poll? 30 people voted for Whitney out of a total of 200 votes cast. 30 ÷ 200 = 0.15. Convert 0.15 to a percent by moving the decimal point two places to the right. 0.15 = 15% → Correct answer is A) 15% is x % 30 = → = → of 100 200 100 Cross multiply → 200 x = 3000 → x = 15 → Correct answer is A) 15% ALTERNATIVE WAY: Use proportion → 14) If the poll is indicative of how the 10,000 registered voters of Springdale will actually vote in the election, which of the following is the best estimate of the number of votes Lue will receive in the election? 80 x = → 200 x = 800000 200 10000 Divide both sides by 200 → x = 4000 → Correct answer is H) 4,000 Set up a proportion and cross-multiply: 15) If the information in the table were converted into a circle graph (pie chart), then the central angle of the sector for Gomez would measure how many degrees? There are 360° in a circle. Set up a proportion and cross-multiply: 40 x = → 200 x = 14400 → Divide both sides by 200 → x = 72 200 360 Correct answer is B) 72° 16. In square ABCE shown below, D is the midpoint of CE . Which of the following is the ratio of the area of Δ ADE to the area of Δ ADB? D Since no side lengths are given, I made up a side length for the square ABCE of 4 cm. E 4 cm DE = 1/2 ∗ 4 cm = 2 cm Area of + ADE = 1/2 ∗ 2 cm ∗ 4 cm = 4 cm 2 Area of + ADB = 1/2 ∗ 4 cm ∗ 4 cm = 8 cm Ratio of + ADE to + ADB = 17. 2 C 4 cm A 4 cm B 4 cm 2 1 = → Correct answer is G) 1:2 8 cm 2 2 Which of the following is the slope of a line parallel to the line y = in the standard (x, y) coordinate plane? Parallel lines have the same slope. Slope-intercept form: y = mx + b, where m = slope and b = y-intercept 2 2 2 y = x − 4 → m = , b = −4 → slope = , y -intercept = −4 3 3 3 2 Correct answer is E) 3 2 x−4 3 18. Janelle cut a board 30 feet long into 2 pieces. The ratio of the lengths of the 2 pieces is 2 : 3. What is the length, to the nearest foot, of the shorter piece? If the pieces are in the ratio of 2 : 3, call the shorter piece 2x and the longer piece 3x. 3x 2x 30 feet 2 x + 3x = 30 → 5 x = 30 → x = 6 → Shorter piece = 2 x = 2 ∗ 6 = 12 feet Correct answer is H) 12 19. What is the smallest integer greater than 58 ? Use your calculator to evaluate 58 → 58 ≈ 7.61 → First integer > 7.61 is 8 Correct answer is C) 8 20. Sergio plans to paint the 4 walls of his room with 1 coat of paint. The walls are rectangular, and, according to his measurements, each wall is 10 feet by 15 feet. He will not need to paint the single 3-foot-by-5-foot rectangular window in his room and the 3½-foot-by-7-foot rectangular door. Sergio knows that each gallon of paint covers between 300 and 350 square feet. If only 1-gallon cans of paint are available, which of the following is the minimum number of cans of paint Sergio needs to buy to paint his walls? Area of each rectangular wall = 10 ft ∗15 ft = 150 ft 2 → 4 walls = 4 ∗150 ft 2 = 600 ft 2 Area of window = 3 ft ∗ 5 ft = 15 ft 2 , Area of door = 3.5 ft ∗ 7 ft = 24.5 ft 2 Total area to be painted = 600 ft 2 − 15 ft 2 − 24.5 ft 2 = 560.5 ft 2 1 can of paint covers 300 ft2 - 350 ft2, 2 cans of paint covers 600 ft2 - 700 ft2 1 can is not enough to cover 560.5 ft2, but 2 cans are enough Correct answer is G) 2 21. What values of x are solutions for x 2 + 2 x = 8? This is a quadratic equation, so it can be solved by factoring or the Quadratic Formula. In either case, the equation must be set equal to 0 first. x 2 + 2 x = 8 → x 2 + 2 x − 8 = 0 → ( x + 4 )( x − 2 ) = 0 → x + 4 = 0 or x − 2 = 0 → x = −4 or x = 2 → Correct answer is A) − 4 and 2 22. For all a > 1, the expression 3a 4 equals: 3a 6 3a 4 3∗ a ∗ a ∗ a ∗ a 1 1 1 = = = 2 → Correct answer is K) 2 6 3a 3∗ a ∗ a ∗ a ∗ a ∗ a ∗ a a ∗ a a a ALTERNATIVE WAY: Reduce 3 in top and bottom, reduce powers by subtracting 3a 4 1 1 exponents → 6 = a 4−6 = a −2 = 2 → Correct answer is K) 2 3a a a 23. 24. If point M has a nonzero x-coordinate and a nonzero y-coordinate and the coordinates have opposite signs, then point M must be located in which of the 4 quadrants below? Ordered pairs with opposite signs will appear in Quadrant II and Quadrant IV. Correct answer is E) II or IV only Quadrant II x negative, y positive Quadrant I x positive, y positive Quadrant III x negative, y negative Quadrant IV x positive, y negative The fixed costs of manufacturing basketballs in a factory are $1,400.00 per day. The variable costs are $5.25 per basketball. Which of the following expressions can be used to model the cost of manufacturing b basketballs in 1 day? $1,400.00 is spent every day, regardless of the number of basketballs made. The cost of manufacturing 1 basketball is $5.25, so the cost of manufacturing b basketballs is $5.25 * b, or $5.25b. The total manufacturing cost per day is fixed cost ($1,400.00) + variable cost ($5.25b) → Correct answer is K) $1,400.00 + $5.25b 25. In the figure below, where Δ ABC ~ Δ KLM, lengths are given in centimeters. What is the perimeter, in centimeters, of Δ ABC? NOTE: The symbol ~ means “is similar to.” L 12.5 The ratio of the perimeters of the two triangles is the same as the ratio of any two corresponding sides. B A The perimeter of Δ KLM = 12.5 + 7.5 + 15 = 35. 3 AC Perimeter of + ABC 3 p = → = → C 7.5 35 KM Perimeter of + KLM Cross multiply → 7.5 p = 105 → p = 14 → Correct answer is B) 14 26. If 3 7 a 7 = K 7.5 15 M 3 7 is true, then a = ? 7 3 7 3 7 = → If the numerators are equal, then the denominators must be equal → 7 a 7 a 7 7 7 7∗ 7 7 7 = →a= →a= →a= →a= 7 7 7 7 7 7∗ 7 Correct answer is G) 7 a 7 =7→ ALTERNATIVE WAY: Cross multiply → a 7 ∗ 3 7 = 3 7 ∗ 7 → 3a ∗ 7 = 21 7 → 21a = 21 7 → a = 7 → Correct answer is G) 7 27. A hot-air balloon 70 meters above the ground is falling at a constant rate of 6 meters per second while another hot-air balloon 10 meters above the ground is rising at a constant rate of 15 meters per second. To the nearest tenth of a second, after how many seconds will the 2 balloons be the same height above the ground? Distance between upper balloon and lower balloon = 70 m – 10 m = 60 m Distance formula → Distance = Rate ∗ Time Rate of upper balloon = 6 m/sec Distance covered by upper balloon → D = r ∗ t → D = 6 ∗ t → D = 6t Rate of lower balloon = 15 m/sec Distance covered by lower balloon → D = r ∗ t → D = 15 ∗ t → D = 15t Dupper + Dlower = 60 → 6t + 15t = 60 → 21t = 60 → t = 2.86 seconds → Correct answer is C) 2.9 60 m 70 m 10 m 28. A hiking group will go from a certain town to a certain village by van on 1 of 4 roads, from the village to a waterfall by riding bicycles on 1 of 2 bicycle paths, and then from the waterfall to their campsite by hiking on 1 of 6 trails. How many routes are possible for the hiking group to go from the town to the village to the waterfall to their campsite? Town-village roads (4) * village-waterfall paths (2) * waterfall-campsite trails (6) = 4 ∗ 2 ∗ 6 = 48 possible routes → Correct answer is J) 48 29. Cube A has an edge length of 2 inches. Cube B has an edge length double that of Cube A. What is the volume, in cubic inches, of Cube B? If cube B has a edge length double that of Cube A, then Cube B has an edge length of 4 in. In a cube, the length, the width, and the height are all the same. V = Length ∗ Width ∗ Height → V = 4 in ∗ 4 in ∗ 4 in = 64 in 3 → Correct answer is E) 64 30. A formula used to compute the current value of a savings account is A = P(1 +r)n, where A is the current value; P is the amount deposited; r is the rate of interest for 1 compounding period, expressed as a decimal; and n is the number of compounding periods. Which of the following is closest to the value of a savings account after 5 years if $10,000 is deposited at 4% annual interest compounded yearly? P = 10000, r = 0.04 ( 4% as a decimal ) , n = 5 A = 10000 ∗ (1 + 0.04 ) → A = 10000 ∗ (1.04 ) → A = 10000 ∗1.2166529024 → A = $12,166.53 → Correct answer is G) $12,167 5 31. 5 A right circular cylinder is shown in the figure below, with dimensions given in centimeters. What is the total surface area of this cylinder, in square centimeters? NOTE: The total surface area of a cylinder is given by 2πr2 + 2πrh where r is the radius and h is the height. Diameter of cylinder = 20 → Radius of cylinder = 10 Surface Area = 2π r 2 + 2π rh → A = 2 ∗ π ∗102 + 2 ∗ π ∗10 ∗ 20 → A = 2 ∗ π ∗100 + 400π → A = 200π + 400π → A = 600π → Correct answer is D) 600π 20 20 32. Given f(x) = 4x + 1 and g(x) = x2 – 2, which of the following is an expression for f[g(x)]? To evaluate f ⎡⎣ g ( x ) ⎤⎦ , replace every instance of x in f ( x ) with algebraic expression from g ( x ) . → f ⎡⎣ g ( x ) ⎤⎦ = f ( x 2 − 2 ) = 4 ( x 2 − 2 ) + 1 = 4 x 2 − 8 + 1 = 4 x 2 − 7 → Correct answer is H) 4 x 2 − 7 33. The table below shows the total number of goals scored in each of 43 soccer matches in a regional tournament. Total number of goals in a match 0 1 2 3 4 5 6 7 Number of matches with this total 4 10 5 9 7 5 1 2 Total goals scored in 4 matches : 4 ∗ 0 = 0 Total goals scored in 10 matches : 10 ∗1 = 10 Total goals scored in 5 matches : 5 ∗ 2 = 10 Total goals scored in 9 matches : 9 ∗ 3 = 27 Total goals scored in 7 matches : 7 ∗ 4 = 28 Total goals scored in 5 matches : 5 ∗ 5 = 25 Total goals scored in 1 matches : 1 ∗ 6 = 6 Total goals scored in 2 matches : 2 ∗ 7 = 14 Total goals scored in 43 matches : 0 + 10 + 10 + 27 + 28 + 25 + 6 + 14 = 120 goals Average number of goals: 120 ÷ 43 = 2.791 goals/game → Correct answer is B) 2.8 34. Lines a, b, c, and d are shown below and a || b. Which of the following is the set of all angles that must be supplementary to ∠ x? ∠ x and ∠ 1 are supplementary, because they form a linear pair ∠ x and ∠ 2 are supplementary, because they form a linear pair ∠ 2 ≅ ∠ 10, because they are corresponding ∠s formed by parallel lines ∠ 1 ≅ ∠ 9, because they are corresponding ∠s formed by parallel lines Correct answer is H) {1, 2, 9, 10} 35. ( 3x ) 3 (3x ) 3 3 36. 3 a b x 1 2 3 8 9 10 11 12 13 14 15 4 5 6 7 c d is equivalent to: = 33 ∗ ( x 3 ) = 27 x 9 → ( x a ) = x a∗b → Correct answer is E) 27 x 9 3 b Which of the following is equivalent to the inequality 4x – 8 > 8x + 16? 4 x − 8 > 8 x + 16 → −4 x − 8 > 16 → −4 x > 24 → x < −6 → Correct answer is F) x < −6 When you divide both sides of an inequality by a negative number, the direction of the inequality arrow is reversed. 37. As shown in the standard (x, y) coordinate plane below, P (6, 6) lies on the circle with center (2, 3) and radius 5 coordinate units. What are the coordinates of the image of P after the circle is rotated 90° clockwise about the center of the circle? Slope of a line = rise run 8 P (6, 6) 6 3 ( rise ) 3 Slope of line joining center and P = = 4 ( run ) 4 Point P is rotated 90° clockwise → The line that joins the center and this new point must be ⊥ to the previous line. Lines that are ⊥ have slopes that are opposite reciprocals. Opposite reciprocal of −4 ( rise ) 4 ( rise ) 3 4 is − , either or 4 3 3 ( run ) −3 ( run ) 4 2 (2, 3) 5 10 -2 −4 ( rise ) from center gives point ( 5, − 1) ← 90° clockwise 3 ( run ) 4 ( rise ) from center gives point ( −1, 7 ) ← 90° counter-clockwise −3 ( run ) Correct answer is C) ( 5, − 1) 38. For right triangle Δ KLM below, what is sin ∠ M? Calculate m using Pythagorean Theorem → 102 + m 2 = 122 → K 100 + m = 144 → m = 44 → m = 44 → m = 44 2 sine = 2 2 12 cm opposite leg 44 → sin ∠ M = → hypotenuse 12 Correct answer is K) 44 12 m M 10 cm L 39. In the figure below, B lies on AC , BD bisects ∠ ABE , and BE bisects ∠ CBD. What is the measure of ∠ DBE ? D If BD bisects ∠ ABE , then ∠ ABD ≅ ∠ DBE. E If BE bisects ∠ CBD, then ∠ DBE ≅ ∠ EBC. If ∠ ABD ≅ ∠ DBE and ∠ DBE ≅ ∠ EBC , then ∠ ABD ≅ ∠ EBC. ∠ ABD + ∠ DBE + ∠ EBC = 180° A B If these three angles add up to 180° and are all congruent, then each angle equals 180° ÷ 3 = 60° → Correct answer is B) 60° 40. C If there are 8 x 1012 hydrogen molecules in a volume of 4 x 104 cubic centimeters, what is the average number of hydrogen molecules per cubic centimeter? Molecules 8 × 1012 = = 2 ×108 ( 8 ÷ 4 = 2, 1012 ÷ 104 = 1012− 4 = 108 ) 4 Volume 4 ×10 Correct answer is H) 2 × 108 41. In the figure below, a radar screen shows 2 ships. Ship A is located at a distance of 20 nautical miles and bearing 170°, and ship B is located at a distance of 30 nautical miles and bearing 300°. Which of the following is an expression for the straight-line distance, in nautical miles, between the 2 ships? NOTE: For Δ ABC with side of length a opposite ∠ A, side of length b opposite ∠ B, and side length c opposite ∠ C, the law of cosines states that c2 = a2+b2 – 2ab * cos ∠ C. Side a is opposite ∠ A → a = 30 Side b is opposite ∠ B → b = 20 ∠ C = 300° − 170° = 130° c 2 = a 2 + b 2 − 2 ∗ a ∗ b ∗ cos C → c 2 = 30 2 + 20 2 − 2 ∗ 30 ∗ 20 ∗ cos130° → N B c 2 = 302 + 202 − 2 ∗ 30 ∗ 20 ∗ cos130° → 30 c = 302 + 202 − 2 ∗ 30 ∗ 20 ∗ cos130° → Correct answer is B) 20 + 30 − 2 ( 20 )( 30 ) cos130° 2 2 C c 130° 20 A 170° 300° 42. What rational number is halfway between 1 1 and ? 5 3 1 3 1 5 3 5 4 4 = → Correct answer is J) and = → Halfway between and is 5 15 3 15 15 15 15 15 43. In isosceles trapezoid ABCD, AB is parallel to DC , ∠ BDC measures 25°, and ∠ BCA measures 35°. What is the measure of ∠ DBC ? If ∠ BDC = 25°, then ∠ ACD = 25° ∠ DXC = 180° − 25° − 25° = 130° ∠ BXC = 180° − 130° = 50° ∠ XBC = 180° − 50° − 35° = 95° ∠ XBC and ∠ DBC are the same angle Correct answer is B) 95° A B X 130° 25° D 50° 95° 35° 25° C ALTERNATIVE WAY: If ∠ BDC = 25°, then ∠ ACD = 25° ∠ BCD = 25° + 35° = 60° ∠ DBC = 180° − 25° − 60° = 95° 44. In the figure below, the area of the larger square is 50 square centimeters and the area of the smaller square is 18 square centimeters. What is x, in centimeters? Area of square = side2 Area of large square = 50 → side 2 = 50 → side 2 = 50 → side of large square = 50 = 25 ∗ 2 = 5 2 Area of small square = 18 → side 2 = 18 → side2 = 18 → side of small square = 18 = 9 ∗ 2 = 3 2 x = side of large square − side of small square = 5 2 − 3 2 = 2 2 Correct answer is G) 2 2 45. Which of the following is a rational number? A rational number is any number that can be expressed as a fraction with an integer in both the numerator and denominator. The majority of square roots are irrational, which eliminates 2, π , and 7. 5 5 5 = = → Again, most square roots are irrational. 25 5 25 64 64 8 = = → This number is rational. Correct answer is E) 49 49 7 46. 64 49 If a < b, then |a – b| is equivalent to which of the following? Just use trial & error with a set of numbers: a = 3, b = 4 → a < b Does a − b = a + b ? → 3 − 4 = −1 = 1, 3 + 4 = 7 → NO Does a − b = − ( a + b ) ? → 3 − 4 = −1 = 1, − ( 3 + 4 ) = −7 → NO Does a − b = a − b ? → 3 − 4 = −1 = 1, 3 − 4 = −1 = i → NO Does a − b = a − b ? → 3 − 4 = −1 = 1, 3 − 4 = −1 → NO Does a − b = − ( a − b ) ? → 3 − 4 = −1 = 1, − ( 3 − 4 ) = − ( −1) = 1 → YES Correct answer is K) − ( a − b ) 47. Tom has taken 5 of the 8 equally weighted tests in his U. S. History class this semester, and he has an average of exactly 78.0 points. How many points does he need to earn on the 6th test to bring his average score up to exactly 80.0 points? Tom has taken 5 tests and scored an average of 78.0 points. Therefore, he has scored a total of 5 ∗ 78.0 = 390 points. If Tom wants to average 80.0 points after the 6th test, he must score 6 ∗ 80.0 = 480 points. 480 ( points needed ) − 390 ( points scored ) = 90 ( points on 6th test ) Correct answer is A) 90 48. In the complex plane, the horizontal axis is called the real axis and the vertical axis is called the imaginary axis. The complex number a + bi is graphed in the complex plane is comparable to the point (a, b) graphed in the standard (x, y) coordinate plane. The modulus of the complex number a + bi is given by a 2 + b2 . Which of the complex numbers z1 , z2 , z3, , z4 , and z5 below has the greatest modulus? imaginary axis z1 In the standard ( x, y ) coordinate plane, a 2 + b 2 represents the distance from the origin to the point ( a, b ) . The modulus essentially does the same for the complex plane. Which point looks the farthest from the origin? z1 looks the farthest away from the origin. Correct answer is F) z1 49. z5 z2 real axis O z4 z3 In the real numbers, what is the solution of the equation 82x + 1 = 41 – x? To solve this exponential equation, you must convert both sides of the equation to the same base. 8 = 23 and 4 = 22 → 82 x +1 = 41− x → ( 23 ) 2 x +1 = ( 22 ) 1− x → 26 x +3 = 22 − 2 x → When you raise a power to another power, you keep the base the same and you multiply the exponents. 1 1 6 x + 3 = 2 − 2 x → 8 x + 3 = 2 → 8 x = −1 → x = − → Correct answer is C) − 8 8 50. ⎛1 ⎞ The graph of the trigonometric function y = 2cos ⎜ x ⎟ is shown below. ⎝2 ⎠ The function is: 2 A function is even if f ( x ) = f ( − x ) . When looking at the graph, f (1) ≈ 1.1 and f ( −1) also ≈ 1.1. f (1) = f ( −1) , so the function is even. -5 Correct answer is F) even ( that is, f ( x ) = f ( − x ) for all x ) . 5 -2 51. An integer from 100 through 999, inclusive, is to be chosen at random. What is the probability that the number chosen will have 0 as at least 1 digit? List all the numbers from 100 to 199 that contain 0 as a digit: 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 120, 130, 140, 150, 160, 170, 180, 190 = 19 numbers How many numbers between 200 and 299 contain 0 as a digit? Also 19 numbers. How many numbers between 300 and 399 contain 0 as a digit? Also 19 numbers. How many numbers between 400 and 499 contain 0 as a digit? Also 19 numbers. How many numbers between 500 and 599 contain 0 as a digit? Also 19 numbers. How many numbers between 600 and 699 contain 0 as a digit? Also 19 numbers. How many numbers between 700 and 799 contain 0 as a digit? Also 19 numbers. How many numbers between 800 and 899 contain 0 as a digit? Also 19 numbers. How many numbers between 900 and 999 contain 0 as a digit? Also 19 numbers. How many numbers between 100 and 999 contain 0 as a digit? 9 * 19 = 171 How many total numbers exist between 100 and 999? 999 – 100 + 1 = 900 Desired outcomes 171 171 = → Correct answer is D) Probability = Possible outcomes 900 900 52. In the figure below, line q in the standard (x, y) coordinate plane has equation –2x + y = 1 and intersects line r, which is distinct from line q, at a point on the x-axis. The angles, ∠a and ∠b, formed by these lines and the x-axis are congruent. What is the slope of line r? 4 rise run 1 Slope of line q = = 1 ÷ 0.5 = 2 0.5 1 Slope of line r = = 1 ÷ ( −0.5) = −2 −0.5 Correct answer is F) − 2 Slope of a line = r b 2 -2 q a O 53. In the right triangle below, 0 < b < a. One of the angle measures in the triangle ⎡ ⎛a⎞ ⎛ a ⎞⎤ is tan−1 ⎜ ⎟ . What is cos ⎢tan−1 ⎜ ⎟ ⎥ ? ⎝b⎠ ⎝ b ⎠⎦ ⎣ opposite leg adjacent leg tan = & cos = adjacent leg hypotenuse Which acute angle in the triangle has a tangent ratio a a of → tan ( ∠ A) = b b ⎡ b ⎛ a ⎞⎤ → cos ⎢ tan −1 ⎜ ⎟ ⎥ = cos [ ∠ A] = 2 ⎝ b ⎠⎦ ⎣ a + b2 b Correct answer is D) a 2 + b2 C a B b a 2 + b2 A Use the following information to answer questions #54 – #56. The radio signal from the transmitter site of radio station WGGW can be received only with a radius of 52 miles in all directions from the transmitter site. A map of the region of coverage of the radio signal is shown to the right in the standard (x, y) coordinate plane, with the transmitter site at the origin and 1 coordinate unit representing 1 mile. 54. y 52 x O Which of the following is closest to the area, in square miles, of the region covered by the radio signal? Area of a circle = π ∗ Radius 2 → A = π ∗ 52 2 → A ≈ 8494.9 mile 2 Correct answer is J) 8,500 55. 52 Which of the following is an equation of the circle shown on the map? The equation of a circle with its center at the origin is x 2 + y 2 = Radius 2 → The radius is 52 miles → Correct answer is E) x 2 + y 2 = 522 56. The transmitter site of radio station WGGW and the transmitter of another radio station, WGWB, are on the same highway 100 miles apart. The radio signal from the transmitter site of WGWB can be received only within a radius of 60 miles in all directions from the WGWB transmitter site. For how many miles along the highway can the radio signals of both stations be received? NOTE: Assume the highway is straight. Distance from WGGW to point D = 100 − 60 = 40 m Distance from WGGB to point C = 100 − 52 = 48 m The road from D to C represents when both signals can be heard Distance from D to C = 100 − 40 − 48 = 12 m → Correct answer is G) 12 57. 60 m 52 m WGGW 40 m D C 48 m WGWB The graphs of the equations y = x – 1 and y = (x – 1)4 are shown in the standard (x, y) coordinate plane. What real values of x, if any, satisfy the inequality (x – 1)4 < x – 1? The graph of y = x − 1 is drawn in purple. 2 The graph of y = ( x − 1) is drawn in blue. Where on the graph is the blue portion below, or less than, the purple portion? This happens between 1 and 2. Correct answer is E) 1 < x < 2 4 -2 58. For every positive 2-digit number, x, with tens digit t and units digit u, let y be the 2-digit number formed by reversing the digits of x. Which of the following expressions is equivalent to x – y? Just use trial & error with a set of numbers: x = 72, y = 27, t = 7, u = 2 x − y = 72 − 27 = 45 Does x − y = 9 ( t − u ) → x − y = 45, 9 ( t − u ) = 9 ( 7 − 2 ) = 9 ( 5 ) = 45 → YES Does x − y = 9 ( u − t ) → x − y = 45, 9 ( t − u ) = 9 ( 2 − 7 ) = 9 ( −5) = −45 → NO Does x − y = 9t − u → x − y = 45, 9t − u = 9 ∗ 7 − 2 = 63 − 2 = 61 → NO Does x − y = 9u − t → x − y = 45, 9u − t = 9 ∗ 2 − 7 = 18 − y = 11 → NO Does x − y = 0 → x − y = 45 → NO Correct answer is F) 9 ( t − u ) 59. In the figure below, the vertices of Δ ABC has (x, y) coordinates (4, 5), (5, 3), and (1, 3) respectively. What is the area of Δ ABC? 1 ∗ base ∗ height → 2 Base of triangle = 4 units, Height of triangle = 2 units 1 A = ∗ 4 ∗ 2 = 4 → Correct answer is A) 4 2 Area of a triangle = 60. 6 4 2 A (4, 5) 2 C (1, 3) B (5, 3) 5 10 The sum of an infinite geometric series with first term a and common ratio a r < 1 is given by . The sum of a given infinite geometric series is 200, and 1− r the common ratio is 0.15. What is the second term of this series? a a a → 200 = → 200 = → 170 = a 1− r 1 − 0.15 0.85 In a geometric series, each successive term is produced by multiplying the previous term by the common ratio. First term is 170, so second term = 170 * 0.15 = 25.5. Correct answer is F) 25.5 Sum =