Correct Answer: B

Rationale: To find 6.4% of 32, first calculate 6.4% as a decimal (0.064) and then multiply it by 32 to get 2.048. When rounding to the tenths place, 2.048 is rounded to 2.1 because the digit after the tenths place is 8, which is equal to or greater than 5. Choice A is incorrect as it does not reflect the accurate calculation. Choices C and D are also incorrect because they do not match the correct result of multiplying 6.4% by 32 and rounding to the tenths place.

Correct Answer: A

Rationale: To find the product of 375 and 2.3, multiply them: 375 2.3 = 862.5. When multiplying by 2.3, it is important to shift the decimal point appropriately after performing the calculation. Choice A, 862.5, is the correct answer. Choice B, 750, is incorrect because it is the result of multiplying 375 by 2. Choice C, 225.75, is incorrect as it appears to be the result of multiplying the numbers in the wrong order. Choice D, 1125, is incorrect as it seems to be the result of multiplying 375 by 3 instead of 2.3.

Correct Answer: C

Rationale: To convert a decimal to a percent, you multiply by 100 or move the decimal point two places to the right. In this case, 0.64 becomes 64%. Therefore, the correct answer is 64%. Choice A, 0.64%, is incorrect because it does not convert the decimal to a percent. Choice B, 6.4%, is incorrect as it mistakenly moves the decimal point only one place. Choice D, 0.064%, is incorrect as it moves the decimal point three places instead of two.

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.

Correct Answer: D

Rationale: To convert quarts to ounces, you need to multiply by 32 (1 quart = 32 ounces). Therefore, 2 quarts x 32 ounces/quart = 64 ounces. Hence, there are 64 ounces in 2 quarts. Choices A, B, and C are incorrect because they do not reflect the correct conversion factor from quarts to ounces.