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: 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: the speed of the boat in still water in 12 kmph. it can travel downstream through 48 kms in 3 hrs. in what time would it cover the same distance upstream ?
Options: a. 8 hours, b. 6 hours, c. 4 hours, d. 5 hours, e. 6 hours

A: e
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Q: Problem: in a school of 850 boys, 46 % of muslims, 28 % hindus, 10 % sikhs and the remaining of other communities. how many belonged to the other communities ?
Options: a. a. 136, b. b. 627, c. c. 153, d. d. 721, e. e. 159

A:
a
****