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.

Ex Input:
Problem: a man goes to shopkeeper and says that if u give me as much as i have, i will spend rs. 10 / - on ur shop. shopkeeper agrees and man moves to another shopkeeper ans asked same. at 3 rd shop after all the transaction, he was left with no money. find the initial amount with the man
Options: a. 5.75, b. 6.75, c. 7.75, d. 8.75, e. 9.75

Ex Output:
d


Ex Input:
Problem: each of the three people individually can complete a certain job in 3, 4, and 6 hours, respectively. what is the lowest fraction of the job that can be done in 1 hour by 2 of the people working together at their respective rates ?
Options: a. 1 / 3, b. 9 / 20, c. 8 / 15, d. 5 / 12, e. 2 / 3

Ex Output:
d


Ex Input:
Problem: a train travels at the rate of 10 miles / hr for the first hour of a trip, at 20 miles / hr for the second hour, at 30 miles / hr for the third hour and so on. how many hours will it take the train to complete a 360 - mile journey ? assume that the train makes no intermediate stops.
Options: a. 8, b. 8.5, c. 9, d. 9.5, e. 10

Ex Output:

a