Correct Answer: A

Rationale: The formula for the circumference of a circle is C = πd, where C is the circumference and d is the diameter. Given C = 49 feet, we can rearrange the formula to solve for d: 49 feet = πd. To find the diameter, we divide both sides by π, giving us d = 49 feet / π ≈ 15.6 feet. Therefore, the diameter of the swimming pool is approximately 15.6 feet. Choices B, C, and D are incorrect because they do not align with the calculation based on the formula for the circumference of a circle.

Correct Answer: B

Rationale: To identify the negative value, simplify each expression. A) simplifies to 6 which is positive. B) simplifies to 0 which is neither positive nor negative. C) simplifies to -11 which is negative. D) simplifies to -30 which is negative. Therefore, only choice B results in a non-negative value, making it the correct answer.

Correct Answer: B

Rationale: Using PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction): (3/2)(8/3) · (5/4) = (24/6) · (5/4) = (4/1) · (5/4). To divide fractions, the second fraction is flipped and then multiplied by the first fraction, resulting in (4/1)(4/5) = (16/5), which simplifies to 3(1/5) or 2.

Correct Answer: B

Rationale: To convert 8 pounds and 8 ounces to kilograms, first convert 8 ounces to pounds by dividing by 16 (since 1 pound = 16 ounces): 8 ounces / 16 = 0.5 pounds. Then add this to the original 8 pounds: 8 pounds + 0.5 pounds = 8.5 pounds. To convert pounds to kilograms, use the conversion factor 1 pound = 0.453592 kilograms. Therefore, 8.5 pounds 0.453592 kg = 3.855 kilograms, which rounds to 3.9 kilograms. Choice A (3.6 kilograms), Choice C (17.6 kilograms), and Choice D (18.7 kilograms) are incorrect conversions or have errors in calculation compared to the correct conversion of 3.9 kilograms.

Correct Answer: A

Rationale: To find the discount amount, calculate 20% of $30: 0.20 $30 = $6. Subtract the discount from the original price to get the sale price: $30 - $6 = $24. Therefore, the correct answer is $24. Choices B, C, and D are incorrect as they do not reflect the correct calculation of applying a 20% discount to the original price of $30.