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 denominator of a fraction is 7 greater than the numerator. if the numerator and the denominator are increased by 4, the resulting fraction is equal to 5 â  „ 6. what is the value of the original fraction ?
Options: a. 23 / 30, b. 25 / 32, c. 31 / 38, d. 37 / 44, e. 47 / 54

A: c
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Q: Problem: solution y is 30 percent liquid x and 70 percent water. if 2 kilograms of water evaporate from 6 kilograms of solution y and 2 kilograms of solution y are added to the remaining 4 kilograms of liquid, what percent of this new solution is liquid x ?
Options: a. 33 %, b. 35 1 / 2 %, c. 37 %, d. 40 %, e. 42 %

A: d
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Q: Problem: the average of the marks of 30 students in a class is 45. if the marks of each student are doubled, find the new average ?
Options: a. 85, b. 77, c. 33, d. 90, e. 75

A:
d
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