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If Kevin can wash 30 cars in 15 minutes, how many minutes will it take him to wash 100 cars?
- A. 50 minutes
- B. 55 minutes
- C. 30 minutes
- D. 45 minutes
Correct Answer: A
Rationale: To find out how many minutes Kevin will take to wash 100 cars, set up a proportion: 30 cars is to 15 minutes as 100 cars is to x minutes. Cross multiplying gives 30x = 1500. Solving for x, x = 1500 / 30 = 50. Therefore, it will take Kevin 50 minutes to wash 100 cars. Choice A is correct. Choice B, C, and D are incorrect as they do not correctly calculate the time needed based on the given information.
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What is the result of dividing 3.44 by 0.6?
- A. 11.41
- B. 5.73
- C. 2.33
- D. 0.57
Correct Answer: B
Rationale: The correct answer is B: 5.73. When dividing 3.44 by 0.6, the calculation is 3.44 · 0.6 = 5.73. Choice A (11.41) is incorrect because it is the result of multiplying, not dividing. Choice C (2.33) and Choice D (0.57) are also incorrect results obtained by incorrect calculations.
How many pounds are in 48 ounces?
- A. 3 lbs
- B. 6 lbs
- C. 4 lbs
- D. 8 lbs
Correct Answer: A
Rationale: To convert ounces to pounds, you need to know that there are 16 ounces in a pound. Therefore, to find out how many pounds are in 48 ounces, you divide 48 by 16: 48 · 16 = 3 pounds. This means that 48 ounces is equivalent to 3 pounds. Choice B, 6 lbs, is incorrect as it doesn't correctly convert 48 ounces to pounds. Choice C, 4 lbs, is incorrect as it doesn't take into account the conversion factor of 16 ounces per pound. Choice D, 8 lbs, is also incorrect as it doesn't reflect the accurate conversion of ounces to pounds.
Convert 5/8 to a decimal.
- A. 0.625
- B. 0.5
- C. 0.4
- D. 0.75
Correct Answer: A
Rationale: To convert 5/8 to a decimal, divide 5 by 8: 5 · 8 = 0.625. The correct answer is A (0.625). Choice B (0.5) is incorrect because it represents 1/2. Choice C (0.4) is incorrect because it represents 2/5. Choice D (0.75) is incorrect because it represents 3/4.
You need to buy cardboard to cover a rectangular box with dimensions 40cm by 30cm by 25cm. Considering only the exterior surfaces (not flaps or openings), how much cardboard do you need (assume one sheet covers 0.5 sq m)?
- A. 0.3 sq m
- B. 0.6 sq m
- C. 1.2 sq m
- D. 1.8 sq m
Correct Answer: C
Rationale: To find the total surface area of the rectangular box, calculate the area of each side and sum them up. The areas of the sides are: 2(40x30) + 2(40x25) + 2(30x25) = 2400 + 2000 + 1500 = 5900 sq cm. Convert this to square meters by dividing by 10,000: 5900/10,000 = 0.59 sq m. Since one sheet covers 0.5 sq m, you would need 2 sheets to cover the box fully, which equals 1 sq m. Therefore, the correct answer is 1.2 sq m. Choice A (0.3 sq m) is too small for the dimensions provided. Choice B (0.6 sq m) is incorrect as it doesn't match the calculated surface area. Choice D (1.8 sq m) is too high for the surface area of the box.
Solve for x: 4x + 2 = 18.
- A. x = 4
- B. x = 4
- C. x = 5
- D. x = 3
Correct Answer: B
Rationale: To solve for x, first, subtract 2 from both sides of the equation: 4x = 16. Then, divide by 4 to isolate x: x = 4. Choice A, x = 4, is the correct answer as calculated. Choice C, x = 5, is incorrect because the correct value of x is 4, not 5. Choice D, x = 3, is incorrect as well, as the correct value of x is 4, not 3.