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.

Problem: a and b invests rs. 2500 and rs. 4000 respectively in a business. if a doubles his capital after 6 months. in what ratio should a and b divide that year ' s profit ?
Options: a. 11: 5, b. 15: 16, c. 15: 2, d. 9: 9, e. 11: 1
b

Problem: find the sum of first 89 odd numbers
Options: a. 7921, b. 4800, c. 7900, d. 4980, e. 4960
a

Problem: a fruit seller had some apples. he sells 50 % apples and still he has 5000. originally he had how many apples ?
Options: a. 10000, b. 15200, c. 11005, d. 12540, e. 12450

a