Correct Answer: C

Rationale: To find the total amount spent by the roommates, you need to add up the individual amounts each roommate contributed. Anna contributed $18, Liz contributed $12, and Jane contributed $6. Adding these amounts together gives us $18 + $12 + $6 = $36. Therefore, the correct answer is $36. Option A ($34), Option B ($35), and Option D ($37) are incorrect as they do not match the correct calculation of the total amount spent by the roommates.

Correct Answer: A

Rationale: To find the volume of a sphere, the formula V = (4/3)πr³ is used, where r is the radius of the sphere. Given that the diameter of the ball is 7 inches, the radius (r) would be half of the diameter, which is 3.5 inches. Plugging this value into the formula: V = (4/3)π(3.5)³ = (4/3)π(42.875) ≈ 165.7 in³. Therefore, the correct answer is A. Choice B, C, and D are incorrect as they do not accurately represent the volume of the ball with a diameter of 7 inches.

Correct Answer: C

Rationale: To determine how many prizes should be awarded to 5th-grade students, we need to set up the proportion of the number of 5th-grade students to the total number of students in the school. The total number of students is 35 + 38 + 38 + 33 + 36 = 180 students. To find the proportion of 5th-grade students, it would be 36/180 = 0.2. Since there are 20 prizes to be awarded, multiplying 0.2 by 20 gives us 4, which means 4 prizes should go to the 5th-grade students. Therefore, the correct answer is 4. Choice A (5) is incorrect as it does not align with the proportional distribution. Choice B (4) is the correct answer, as calculated. Choice C (7) is incorrect as it exceeds the total number of prizes available. Choice D (3) is incorrect as it does not match the proportional distribution based on the number of students.

Correct Answer: C

Rationale: To calculate the percent decrease in snowfall between the two winters, use the formula: Percent Decrease = ((Initial Value - Final Value) / Initial Value) * 100. In this case, the initial value is 6 inches and the final value is 3 inches. Plug these values into the formula: ((6 - 3) / 6) * 100 = (3 / 6) * 100 = 0.5 * 100 = 50%. Therefore, the correct answer is 50%, which is not listed among the choices provided. Among the given choices, the closest percentage is 41.00%, which corresponds to choice C.

Correct Answer: D

Rationale: To find the percentage difference in female staff members between City Y and City X, you subtract the percentage of female staff members in City X from the percentage in City Y. So, 60% (City Y) - 40% (City X) = 20%. This means there are 20% more female staff members in City Y compared to City X. Choices A, B, and C are incorrect percentages and do not accurately represent the 20% difference between the two cities.