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: 3 ltr of water is added with 9 ltr of a solution containing 57 % of alcohol in the water. the % of alcohol in the new mixture is ?
Options: a. 41.5 %, b. 42.75 %, c. 43 %, d. 45 %, e. 45.75 %
Example Output: b

Example Input: Problem: a cricket player whose bowling average was 23.50 runs per wicket, takes 5 wicket for 52 runs in a match. due to this his average decreases by 0.50. what will be the number of wickets taken by him till the last match ?
Options: a. 64, b. 72, c. 131, d. 456, e. 108
Example Output: c

Example Input: Problem: the sum of two numbers is 77. 5 times one number is equal to 6 times the other. the bigger of the two numbers is
Options: a. 10, b. 42, c. 14, d. 15, e. 60
Example Output:
b