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: john and david can finish a job together in 2 hours. if john can do the job by himself in 3 hours, what percent of the job does david do ?
Options: a. 36.33 %, b. 33.33 %, c. 39.33 %, d. 40.33 %, e. 33 %
Example Output: b

Example Input: Problem: jack has two dice, one has 6 equally probable sides, labeled 1, 2, 3, 4, 5, 6, and the other has 7 equally probable sides, labeled 1, 2, 3, 4, 5, 6, 7. if jack rolls both dice what is the probability that both of the number ' s sum will be 13 ?
Options: a. 3 / 14, b. 2 / 7, c. 1 / 3, d. 1 / 42, e. 12 / 21
Example Output: d

Example Input: Problem: every year an amount increases by 1 / 8 th of itself. how much will it be after two years if its present value is rs. 57600 ?
Options: a. 81000, b. 81028, c. 27772, d. 72900, e. 22312
Example Output:
d