In the winter of 2006, 6 inches of snow fell in Chicago, IL. The following winter, 3 inches of snowfall fell in Chicago. What was the percent decrease in snowfall in Chicago between those two winters?

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: C

Rationale: Let's denote the number of cars containing only a man as M, only a woman as W, and both a man and a woman as B. Given that there are 25 cars in total, we have: M + W + B = 25 From the information provided, we know that 13 cars contain a woman (W) and 20 cars contain a man (M). Since each car contains either one man, one woman, or both, the cars that contain both a man and a woman (B) are counted once in each of the M and W categories. Therefore, to find out how many cars contain both a man and a woman, we need to subtract the number of cars that contain only a man and only a woman from the total cars. M + B = 20 (as 20 cars contain a man) W + B = 13 (as 13 cars contain a woman) Solving the above two equations simultaneously, we get: M = 12, W = 5, B = 8 Therefore, 8 cars contain both a man and a woman. Hence, the correct answer is 8. Choice A, B, and D are incorrect as they do not reflect the correct calculation based on the information provided.

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: When reducing a figure by a scale factor, each dimension is multiplied by the same scale factor. In this case, the scale factor is not provided in the question. To find the scale factor, you would divide the new lengths of the sides by the original lengths. The scaled-down triangle's dimensions are the original dimensions multiplied by the scale factor. By performing the calculations, the dimensions of the dilated triangle are 6.75 cm, 3 cm, and 5.25 cm, which matches choice C. Choices A, B, and D have incorrect dimensions as they do not result from the correct application of the scale factor to the original triangle's dimensions.

Correct Answer: B

Rationale: To find the least number of computers that must be shipped and sold so that the amount received is at least equal to the shipping cost, we set up the inequality 400x >= 3000 + 100x. Simplifying this inequality gives 300x >= 3000, and dividing by 300 results in x >= 10. Therefore, at least 15 computers must be shipped and sold to cover the shipping cost, making choice B the correct answer. Choices A, C, and D are incorrect as they represent numbers less than 15, which would not cover the shipping cost.