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: in 10 years, a will be twice as old as b was 10 years ago. if a is now 5 years older than b the present age of b is
Options: a. 37, b. 38, c. 39, d. 35, e. 41

A: d
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Q: Problem: the area of one square is x ^ 2 + 4 x + 4 and the area of another square is 4 x ^ 2 − 12 x + 9. if the sum of the perimeters of both squares is 32, what is the value of x ?
Options: a. 0, b. 2, c. 2.5, d. 4.67, e. 3

A: e
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Q: Problem: 29 persons can repair a road in 16 days, working 5 hours a day. in how many days will 30 persons, working 6 hours a day, complete the work ?
Options: a. 12.88, b. 3.88, c. 13.88, d. 15, e. 18.8

A:
a
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