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.

Input: Consider Input: Problem: a student took 5 papers in an examination, where the full marks were the same for each paper. his marks in these papers were in the proportion of 6: 7: 8: 9: 10. in all papers together, the candidate obtained 60 % of the total marks then, the number of papers in which he got more than 50 % marks is
Options: a. 1, b. 3, c. 4, d. 5, e. 7

Output: c


Input: Consider Input: Problem: if 20 typists can type 50 letters in 30 minutes, then how many letters will 40 typists working at the same rate complete in 1 hour ?
Options: a. 400, b. 500, c. 350, d. 250, e. 200

Output: a


Input: Consider Input: Problem: a can do a piece of work in 80 days. he works at it for 10 days & then b alone finishes the remaining work in 42 days. in how much time will a and b, working together, finish the work ?
Options: a. 30 days, b. 20 days, c. 25 days, d. 35 days, e. 45 days


Output: a