Q: 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.
Problem: 15 men can complete a work in 10 days while 20 boys can complete the same work in 15 days. how many days will 10 men and 10 boys together take to complete the same work
Options: a. 9 days, b. 10 days, c. 11 days, d. 12 days, e. 13 days
A:
b