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: an error 1 % in excess is made while measuring the side of a square. the percentage of error in the calculated area of the square is :
Options: a. 2.01, b. 30.1, c. 3.01, d. 25.01, e. 4.05

A: a
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Q: Problem: the sum of the ages of 5 children born at the intervals of 3 year each is 60 year. what is the age of the youngest child ?
Options: a. 4 year, b. 6 year, c. 10 year, d. none of these, e. 9 year

A: b
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Q: Problem: what is the difference between the c. i. on rs. 9000 for 1 1 / 2 years at 4 % per annum compounded yearly and half - yearly ?
Options: a. s. 2.04, b. s. 2.08, c. s. 3.67, d. s. 2.83, e. s. 2.42

A:
c
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