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 the wages of 6 men for 15 days be rs. 2100, then find the wages of for 12 days.
Options: a. rs. 2420, b. rs. 2500, c. rs. 2520, d. rs. 2020, e. rs. 2650
[EX A]: c

[EX Q]: Problem: in 5 football games thus far this season, barry has run for 98, 107, 85, 89, and 91 yards. at a minimum, how many yards m will he need to gain this sunday if he wants to keep his season average above 100 yards ?
Options: a. 101, b. 116, c. m = 130, d. m = 131, e. m = 141
[EX A]: d

[EX Q]: Problem: a bullet train covers a distance in 50 min, if it runs at a speed of 48 kmph on an average. the speed at which the bullet train must run to reduce the time of journey to 40 min will be.
Options: a. 80 kmph, b. 40 kmph, c. 60 kmph, d. 90 kmph, e. 30 kmph
[EX A]:
c