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: if 50 apprentices can finish a job in 4 hours, and 30 journeymen can finish the same job in 8 hours, how much of the job should be completed by 10 apprentices and 15 journeymen in one hour ?
Options: a. 1 / 9, b. 29 / 180, c. 9 / 80, d. 1 / 5, e. 39 / 121
[A]: c


[Q]: Problem: 12. what is the dividend. divisor 17, the quotient is 9 and the remainder is 10.
Options: a. 150, b. 152, c. 154, d. 163, e. 144
[A]: d


[Q]: Problem: if 0.75: x: : 10: 8, then x is equal to :
Options: a. a. 0.6, b. b. 0.8, c. c. 0.85, d. d. 0.5, e. e. none
[A]:
a