Correct Answer: C

Rationale: To find the product of 99 and 0.56, multiply the two numbers: 99 x 0.56 = 55.44. Therefore, the correct answer is 55.44.

Correct Answer: B

Rationale: To convert ounces to milliliters, we know that 1 ounce is approximately 30 mL. Therefore, 0.5 ounces would be half of that, which is 15 mL. So, 0.5 oz of perfume is equal to 15 mL. Choice A (10 mL), Choice C (20 mL), and Choice D (25 mL) are incorrect as they do not reflect the accurate conversion from ounces to milliliters.

Correct Answer: B

Rationale: To convert 17/80 to a percent, we divide 17 by 80 to get 0.2125. Multiplying by 100, we get 21.25%. Rounding to the nearest whole number, 21.25% becomes 21%. Choice A (20%) is incorrect because rounding 21.25% down to the nearest whole number gives 21%. Choice C (22%) is incorrect as it is the next whole number after 21. Choice D (23%) is incorrect as it is more than 21.25% and thus rounds up to 22%.

Correct Answer: A

Rationale: To convert a percentage to a decimal, you divide by 100. In this case, 38% divided by 100 equals 0.38. Moving the decimal point two places to the left converts the percentage to a decimal. Choice B is incorrect because it incorrectly moves the decimal point one place to the left. Choice C is incorrect as it moves the decimal point three places to the left. Choice D is incorrect as it does not convert the percentage to a decimal.

Correct Answer: B

Rationale: To find the volume of the triangular shelf, first calculate the area of the triangle (1/2 * base * height) which is (1/2 * 40 * 30) = 600 sq cm. Then, multiply this area by the depth of the shelf (600 * 25) = 15000 cu cm. Therefore, the volume of each shelf is 3750 cu cm. Choice A, C, and D are incorrect as they do not correctly calculate the volume based on the dimensions provided.