Solve the equation 8x − 6 = 3x + 24. Which of the following is the correct solution?
- A. x = 2.5
- B. x = 3.6
- C. x = 5
- D. x = 6
Correct Answer: D
Rationale: To solve the equation 8x − 6 = 3x + 24, start by adding 6 to both sides: 8x − 6 + 6 = 3x + 24 + 6, which simplifies to 8x = 3x + 30. Next, subtract 3x from both sides to get 5x = 30. Finally, divide both sides by 5 to solve for x: x = 6. Therefore, the correct solution is x = 6. Choices A, B, and C are incorrect because they do not result from the correct algebraic manipulation of the equation.
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Adam is painting the outside of a 4-walled shed. The shed is 5 feet wide, 4 feet deep, and 7 feet high. Which of the following is the amount of paint Adam will need for the four walls?
- A. 80 ft²
- B. 126 ft²
- C. 140 ft²
- D. 560 ft²
Correct Answer: B
Rationale: To find the amount of paint needed for the four walls of the shed, calculate the total area of the four walls. The shed has two pairs of identical walls. The area of one pair of walls is 5 feet (width) x 7 feet (height) + 4 feet (depth) x 7 feet (height) = 35 ft² + 28 ft² = 63 ft². Since there are two pairs of walls, the total area for the four walls is 2 x 63 ft² = 126 ft². Therefore, Adam will need 126 ft² of paint for the four walls. Choice A, 80 ft², is incorrect as it does not account for the total surface area of all four walls. Choice C, 140 ft², is incorrect as it overestimates the area required. Choice D, 560 ft², is incorrect as it significantly overestimates the amount of paint needed for the shed.
Which of the following is equivalent to 3.28?
- A. (328/100)
- B. (41/5)
- C. (3/28)
- D. (7/25)
Correct Answer: D
Rationale: To convert a decimal to a fraction, we can treat it as a fraction over 1 and then simplify. For 3.28, it can be written as 3.28/1. To convert this to a fraction, we multiply by 100 to get (328/100). Then, to simplify, we divide both the numerator and denominator by 4 to get (82/25). This simplifies further to (7/25). Therefore, (7/25) is equivalent to 3.28. Choices A, B, and C are incorrect as they do not represent the decimal 3.28.
Which of the following is the correct solution to the equation 3x + 4 = 19?
- A. x = 3
- B. x = 4
- C. x = 5
- D. x = 6
Correct Answer: C
Rationale: To solve the equation 3x + 4 = 19, first, subtract 4 from both sides to isolate the term with x, which gives 3x = 15. Then, divide both sides by 3 to solve for x, resulting in x = 5. Therefore, the correct answer is x = 5. Choice A, x = 3, is incorrect as it does not satisfy the equation. Choice B, x = 4, is also incorrect as it does not make the equation true. Choice D, x = 6, is incorrect as it does not align with the correct solution obtained through the proper algebraic steps.
Based on a favorable performance review at work, Matt receives a 3/20 increase in his hourly wage. If his original hourly wage is represented by w, which of the following represents his new wage?
- A. 0.15w
- B. 0.85w
- C. 1.12w
- D. 1.15w
Correct Answer: D
Rationale: To calculate Matt's new wage after a 3/20 increase, we need to add this percentage increase to his original wage. The increase in decimal form is 3/20 = 0.15. Therefore, the new wage is w + w(0.15) = w(1 + 0.15) = 1.15w. This means the correct answer is D. Choices A, B, and C are incorrect because they do not account for the full 3/20 increase in the wage. Choice A (0.15w) represents only the increase percentage, not the total new wage. Choice B (0.85w) and Choice C (1.12w) do not accurately calculate the new wage after the increase, leading to incorrect representations of the final wage.
Melissa is ordering fencing to enclose a square area of 5625 square feet. How many feet of fencing does she need?
- A. 75 feet
- B. 150 feet
- C. 300 feet
- D. 5,625 feet
Correct Answer: C
Rationale: To find the side length of the square, we take the square root of the area: √5625 ft² = 75 ft. The perimeter of a square is 4 times its side length, so the fencing needed is 4 75 ft = 300 ft. Therefore, Melissa needs 300 feet of fencing to enclose the square area of 5625 square feet. Option A (75 feet) is the side length of the square, not the fencing needed. Option B (150 feet) is half of the correct answer and does not account for all sides of the square. Option D (5,625 feet) is the total area, not the length of fencing required.