Correct Answer: A

Rationale: To calculate the number of diapers needed in a year with 6 diaper changes per day, multiply the daily diaper changes (6) by the days in a year (365): 6 x 365 = 2190 diapers required. This calculation ensures an ample supply of diapers for maintaining the infant's hygiene and comfort. The other choices are incorrect because they do not accurately account for the number of diaper changes per day multiplied by the days in a year. Choice B (2100 diapers) is too low, while choices C (2160 diapers) and D (2140 diapers) are too high based on the calculation. Understanding the frequency and quantity of diaper changes is crucial for supporting the infant's health and well-being. Therefore, the correct answer is 2190 diapers.

Correct Answer: B

Rationale: To convert 3 1/2 pints of sour cream to cups, knowing that 1 pint equals 2 cups, we multiply 3.5 by 2, resulting in 7 cups. Therefore, the equivalent amount of sour cream in cups is 7 cups. Choice A is incorrect as it does not consider the correct conversion factor. Choice C is incorrect as it does not account for the accurate conversion from pints to cups. Choice D is incorrect as it underestimates the conversion by not multiplying the pints by the correct factor.

Correct Answer: C

Rationale: To find three tenths of 90, you need to multiply 90 by 0.3 (since three tenths equals 0.3). Therefore, 90 * 0.3 = 27. This calculation shows that the correct answer is 27. Choice A (18), choice B (45), and choice D (36) are incorrect as they do not represent three tenths of 90.

Correct Answer: A

Rationale: To multiply decimals, align the numbers as whole numbers, multiply as if they were whole numbers, then adjust the decimal point in the final answer. When multiplying 0.67 by 0.09, the result is 0.0603. To get this result, multiply 67 by 9 to get 603, then adjust the decimal point two places to the left in the final product, resulting in 0.0603. Choice B, 0.6, is incorrect because it does not account for the decimal precision in the multiplication. Choice C, 0.603, is incorrect as it has the digits reversed when compared to the correct answer. Choice D, 0.06, is incorrect as it does not reflect the correct product of the two decimals being multiplied.

Correct Answer: A

Rationale: Percent (%) represents a value out of 100. To convert 125% to a fraction, it is 125/100. Simplifying 125/100 by dividing both the numerator and denominator by 25 gives us 5/4. Therefore, the correct answer is A. Choice B (1/8), Choice C (5/2), and Choice D (25/2) do not represent 125% as a fraction in lowest terms.