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.

Q: Problem: what is the sum of natural numbers between 30 and 100
Options: a. 4615, b. 4860, c. 5000, d. 5500, e. 5550

A: a
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Q: 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

A: c
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Q: Problem: given that 268 * 74 = 19832, find the values of 2.68 * 0.74.
Options: a. 1.9328, b. 1.9832, c. 1.9823, d. 1.9382, e. none of them

A:
b
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