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: a sum of money at simple interest amounts to rs. 720 after 2 years and to rs. 1020 after a further period of 5 years. the sum is :
Options: a. 400, b. 500, c. 600, d. 700, e. 800

Answer: c

Question: Problem: 3 candidates in an election and received 6136, 7636 and 11628 votes respectively. what % of the total votes did the winning candidate got in that election ?
Options: a. 46 %, b. 49 %, c. 57 %, d. 59 %, e. 61 %

Answer: a

Question: Problem: there are 250 doctors and nurses at a hospital. if the ratio of doctors to nurses is 2 to 3, how many nurses are at the hospital ?
Options: a. 134, b. 138, c. 142, d. 146, e. 150

Answer:
e