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: raman mixed 48 kg of butter at rs. 150 per kg with 36 kg butter at the rate of rs. 125 per kg. at what price per kg should he sell the mixture to make a profit of 40 % in the transaction ?
Options: a. 129, b. 287, c. 195, d. 188, e. 112

A: c
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Q: Problem: john and david can finish a job together in 2 hours. if john can do the job by himself in 3 hours, what percent of the job does david do ?
Options: a. 36.33 %, b. 33.33 %, c. 39.33 %, d. 40.33 %, e. 33 %

A: b
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Q: Problem: a man saves 20 % of his monthly salary. if an account of dearness of things he is to increase his monthly expenses by 20 %, he is only able to save rs. 250 per month. what is his monthly salary ?
Options: a. 5000, b. 2999, c. 2878, d. 6250, e. 2771

A:
d
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