TASK DEFINITION: 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: Problem: the difference between the compound interest compounded annually and simple interest for 2 years at 20 % per annum is rs. 216. find the principal ?
Options: a. 2277, b. 2667, c. 5400, d. 2766, e. 1811

SOLUTION: c

PROBLEM: Problem: the average of first 10 natural numbers is ?
Options: a. 5.6, b. 5.5, c. 5.1, d. 5.8, e. 5.2

SOLUTION: b

PROBLEM: Problem: the average of 7 numbers is 25. if each number be multiplied by 5. find the average of new set of numbers ?
Options: a. a. 110, b. b. 122, c. c. 120, d. d. 125, e. e. 145

SOLUTION:
d