A commuter survey counts the people riding in cars on a highway in the morning. Each car contains only one man, only one woman, or both one man and one woman. Out of 25 cars, 13 contain a woman and 20 contain a man. How many contain both a man and a woman?

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: D

Rationale: To determine the percentage of rainfall received during the month of October, we must first calculate the total rainfall for October and the total rainfall for the entire timeframe. Given that the total rainfall for October is 18.9 inches and the total rainfall from January to November is 106.3 inches, we can proceed with the calculation. The percentage is calculated as (18.9/106.3) x 100 = 17.7%. Therefore, the correct answer is D, 17.7%. Choice A (13.50%), Choice B (15.10%), and Choice C (16.90%) are incorrect as they do not align with the accurate calculation based on the provided data.

Correct Answer: B

Rationale: The square root of 1296 is 36 because 36 multiplied by 36 equals 1296. Therefore, the correct answer is 36. Choices A, C, and D are incorrect. A (24) is not the square root of 1296 because 24 multiplied by 24 is 576, not 1296. C (31) is also incorrect as 31 multiplied by 31 is 961, not 1296. D (12) is not the square root of 1296 as 12 multiplied by 12 equals 144, not 1296.

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: The mean is the average of a set of numbers, while the median is the middle value when the numbers are arranged in order. If a set of numbers is skewed to one side with some outliers, the mean can be influenced by these extreme values, causing it to be greater or less than the median. In cases of skewed distribution, the mean typically shifts towards the direction of the outliers, making it less than the median. Choice B is incorrect because the mode, which is the most frequent number in a dataset, may or may not be greater than the median. Choice C is incorrect because the mode can be greater than the mean or median, depending on the data. Choice D is incorrect because the mode, representing the most frequent value, has no direct relationship with the range, which is the difference between the highest and lowest values in a dataset.

Correct Answer: B

Rationale: Each container of chicken broth contains 410 milliliters. Jennifer added four containers, which totals 4 * 410 = 1640 milliliters of chicken broth. She then added 1 liter of water, equivalent to 1000 milliliters. Combining all the liquids, we get 1640 + 1000 = 2640 milliliters, which equals 2.64 liters. Choice A is incorrect because it miscalculates the total liquid volume. Choice C is incorrect as it greatly overestimates the liquid amount. Choice D is incorrect as it also overestimates the liquid content in the pot.

Correct Answer: A

Rationale: To find the average speed for the round trip, we calculate the total distance and total time traveled. The total distance for the round trip is 45 miles each way, so 45 miles * 2 = 90 miles. The total time taken for the morning trip is 1 hour and 10 minutes (1.17 hours), and for the evening trip is 1.5 hours. Therefore, the total time for the round trip is 1.17 hours + 1.5 hours = 2.67 hours. To find the average speed, we divide the total distance by the total time: 90 miles / 2.67 hours ≈ 33.7 miles per hour. The closest option is A, 30 miles per hour, making it the correct answer. Choice B (45) is the total distance for the round trip, not the average speed. Choices C (36) and D (40) are not derived from the correct calculations and do not represent the average speed for the round trip.

Correct Answer: A

Rationale: The correct answer is $90. If he pays $270 per month in rent and saves a total of $360 per month, he puts $360 - $270 = $90 into his house savings account each month. Choice B ($270) is incorrect as this amount represents the rent paid, not the amount saved. Choices C ($730) and D ($810) are both significantly higher than the correct amount of $90, making them incorrect as they do not align with the given information in the question.

Correct Answer: C

Rationale: When 35% is deducted for taxes and 4% for insurance, the total percentage taken out of the paycheck is 35% + 4% = 39%. Therefore, the correct answer is 39%, which corresponds to option C. Option A (20%) is incorrect because it does not account for the total deductions. Option B (31%) is incorrect as it does not sum up the percentages correctly. Option D (42%) is incorrect as it overestimates the total deductions.