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.
--------
Question: Problem:. 005 / ? =. 01
Options: a.. 5, b.. 05, c.. 005, d.. 0005, e. none of them

Answer: a

Question: Problem: a can do a job in 15 days and b in 20 days. if they work on it together for 4 days, then the fraction of the work that is left is ?
Options: a. 2 / 15, b. 8 / 15, c. 3 / 11, d. 1 / 12, e. 6 / 13

Answer: b

Question: Problem: i had rs. 10000 with me. out of this, money i lent some money to a for 2 years at 15 % simple interest. i lent the remaining money to b for an equal number of years at 18 % simple interest. after 2 years, i found that a had given me rs. 360 more as interest as compared to ( b. the amount of money which i had lent to b must have been
Options: a. 2000, b. 3000, c. 4000, d. 5000, e. 6000

Answer:
c