A quantity increases from 40 to 60. Express this increase as a percentage.
- A. 26%
- B. 50%
- C. 35%
- D. 12%
Correct Answer: B
Rationale: To calculate the percentage increase, use the formula:
Percentage Increase = ((New Value - Original Value) / Original Value) x 100
Substitute the values:
((60 - 40) / 40) x 100 = (20 / 40) x 100 = 0.5 x 100 = 50%
Therefore, the correct answer is 50%.
Choice A (26%) is incorrect as the percentage increase is not 26%. Choice C (35%) is incorrect as the percentage increase is not 35%. Choice D (12%) is incorrect as the percentage increase is not 12%.
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Adrian measures the circumference of a circular picture frame with a radius of 3 inches. Which of the following is the best estimate for the circumference of the frame?
- A. 12 inches
- B. 16 inches
- C. 18 inches
- D. 24 inches
Correct Answer: C
Rationale: To calculate the circumference of a circle, use the formula 2πr, where r is the radius. In this case, with a radius of 3 inches, the estimated circumference would be 2 x π x 3 = 6π ≈ 18.85 inches. Therefore, the best estimate for the circumference of the frame is 18 inches (Choice C). Choice A (12 inches) is too small as it corresponds to the diameter rather than the circumference. Choice B (16 inches) and Choice D (24 inches) are also incorrect as they do not reflect the accurate calculation based on the given radius.
Express the solution to the following problem in decimal form:
- A. 0.042
- B. 84%
- C. 0.84
- D. 0.42
Correct Answer: C
Rationale: The correct answer is C: 0.84. To convert a percentage to a decimal, you divide the percentage value by 100. In this case, 84% divided by 100 equals 0.84. Choice A, 0.042, is not the correct conversion of 84%. Choice B, 84%, is already in percentage form and needs to be converted to a decimal. Choice D, 0.42, is not the correct conversion of 84% either. Therefore, the correct decimal form of 84% is 0.84.
Kimberley earns $10 an hour babysitting, and after 10 p.m., she earns $12 an hour, with the amount paid being rounded to the nearest hour accordingly. On her last job, she worked from 5:30 p.m. to 11 p.m. In total, how much did Kimberley earn on her last job?
- A. $45
- B. $57
- C. $62
- D. $42
Correct Answer: C
Rationale: Kimberley worked from 5:30 p.m. to 11 p.m., which is a total of 5.5 hours before 10 p.m. (from 5:30 p.m. to 10 p.m.) and 1 hour after 10 p.m. The earnings she made before 10 p.m. at $10 an hour was 5.5 hours * $10 = $55. Her earnings after 10 p.m. for the rounded hour were 1 hour * $12 = $12. Therefore, her total earnings for the last job were $55 + $12 = $67. Since the amount is rounded to the nearest hour, the closest rounded amount is $62. Therefore, Kimberley earned $62 on her last job. Choice A is incorrect as it does not consider the additional earnings after 10 p.m. Choices B and D are incorrect as they do not factor in the hourly rates and the total hours worked accurately.
How much did he save from the original price?
- A. $170
- B. $212.50
- C. $105.75
- D. $200
Correct Answer: B
Rationale: To calculate the amount saved from the original price, you need to subtract the discounted price from the original price. The formula is: Original price - Discounted price = Amount saved. In this case, the original price was $850, and the discounted price was $637.50. Therefore, $850 - $637.50 = $212.50. Hence, he saved $212.50 from the original price. Choice A ($170) is incorrect as it is not the correct amount saved. Choice C ($105.75) is incorrect as it does not match the calculated savings. Choice D ($200) is incorrect as it is not the accurate amount saved based on the given prices.
How many kilometers is 4382 feet?
- A. 1.336 kilometers
- B. 14.376 kilometers
- C. 1.437 kilometers
- D. 13.336 kilometers
Correct Answer: A
Rationale: To convert feet to kilometers, you need to divide the number of feet by 3280.84 (the number of feet in a kilometer). Therefore, 4382 feet is equal to 4382/3280.84 ≈ 1.336 kilometers. Choice B, 14.376 kilometers, is incorrect as it seems to be a miscalculation. Choice C, 1.437 kilometers, is also incorrect, as it is slightly off from the correct conversion. Choice D, 13.336 kilometers, is significantly higher than the correct answer and does not align with the conversion factor.