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: in what ratio must a grocer mix two varieties of pulses costing rs. 15 and rs. 20 per kg respectively so as to get a mixture worth rs. 16.50 per kg ?
Options: a. 3: 7, b. 5: 7, c. 7: 3, d. 7: 5, e. none

Answer: c


Question: Problem: if 5 a = 3125, then the value of 5 ( a - 3 ) is :
Options: a. 25, b. 125, c. 625, d. 1625, e. none of these

Answer: a


Question: Problem: if shares of two persons in profits are rs. 400 and rs. 600 then ratio of their capitals is
Options: a. 3: 4, b. 2: 3, c. 4: 3, d. 1: 3, e. 1: 2

Answer:
b