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 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
[EX A]: c

[EX Q]: Problem: 11 is subtracted from 40 % of a number and results is 23. what is the number ?
Options: a. 160, b. 92, c. 88, d. 85, e. 34
[EX A]: d

[EX Q]: Problem: the length of a rectangular plot is thrice its width. if the area of the rectangular plot is 432 sq meters, then what is the width ( in meters ) of the rectangular plot ?
Options: ['a. 10', 'b. 11', 'c. 12', 'd. 13', 'e. 14']
[EX A]:
c

