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.

Example Input: Problem: list r contains 5 numbers that have an average value of 60. if the median of the numbers in the list is equal to the mean and the largest number is equal to 20 more than two times the smallest number, what is the smallest possible value in the list ?
Options: a. 25, b. 28, c. 31, d. 34, e. 37
Example Output: b

Example Input: Problem: anand finishes a work in 7 days, bittu finishes the same job in 8 days and chandu in 6 days. they take turns to finish the work. anand on the first day, bittu on the second and chandu on the third day and then anand again and so on. on which day will the work get over ?
Options: a. 3 rd, b. 6 th, c. 9 th, d. 7 th, e. 8 th
Example Output: d

Example Input: Problem: if the least common multiple of two prime numbers x and y is 10, where x < y, then the value of 3 x + y is
Options: a. 7, b. 9, c. 11, d. 12, e. 21
Example Output:
c