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: a can give b 50 meters start and c 100 meters start in a kilometer race. how much start can b give c in a kilometer race ?
Options: a. 111.12, b. 111.67, c. 111.64, d. 52.63, e. 101.12

A: d
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Q: Problem: a mixture of 70 litres of milk and water contains 10 % water. how many litres of water should be added to the mixture so that the mixture contains 12 1 / 2 % water ?
Options: a. 2, b. 8, c. 6, d. 3, e. 4

A: a
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Q: Problem: the compound ratio of 5: 6, 3: 2 and 4: 5 is ?
Options: a. 3: 5, b. 2: 7, c. 1: 1, d. 1: 4, e. none

A:
c
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