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.

[EX Q]: Problem: if 5 a = 3125, then the value of 5 ( a - 3 ) is :
Options: a. 25, b. 125, c. 625, d. 1625, e. none of these
[EX A]: a

[EX Q]: Problem: if 12 machine can finish a job in 40 days, then how many more machines would be needed to finish the job in one - fourth less time ?
Options: a. a. 4, b. b. 8, c. c. 10, d. d. 12, e. e. 16
[EX A]: a

[EX Q]: Problem: ashok secured average of 74 marks in 6 subjects. if the average of marks in 5 subjects is 74, how many marks did he secure in the 6 th subject ?
Options: a. 66, b. 74, c. 78, d. 80, e. none of these
[EX A]:
b