Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

[Q]: Problem: students at a school were on average 180 cm tall. the average female height was 170 cm, and the average male height was 182 cms. what was the ratio of men to women ?
Options: a. 5: 2, b. 5: 1, c. 4: 3, d. 4: 1, e. 3: 1
[A]: b

[Q]: Problem: p has $ 32 more than what q and r together would have had if both b and c had 1 / 6 of what p has. how much does p have ?
Options: a. $ 44, b. $ 48, c. $ 52, d. $ 56, e. $ 60
[A]: b

[Q]: Problem: on a certain date, pat invested $ 5,000 at x percent annual interest, compounded annually. if the total value of the investment plus interest at the end of 10 years will be $ 20,000, in how many years total will the total value of the investment plus interest increase to $ 40,000 ?
Options: a. 15, b. 16, c. 18, d. 20, e. 24
[A]:
a