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: if the average ( arithmetic mean ) of a and b is 45 and the average of b and c is 80, what is the value of c − a ?
Options: a. 25, b. 60, c. 90, d. 140, e. it can not be determined from the information given.

A: b
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Q: Problem: what will be the compound interest on a sum of rs. 20,000 after 3 years at the rate of 12 % p. a. ?
Options: a. rs. 8098.56, b. rs. 9720, c. rs. 10123.20, d. rs. 10483.20, e. none

A: a
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Q: Problem: if | x + 132 | = 32 what is the sum of all the values of x.
Options: a. - 264, b. 200, c. - 64, d. 0, e. - 328

A:
a
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