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: there are 750 male and female participants in a meeting. half the female participants and one - quarterof the male participants are democrats. one - third of all the participants are democrats. how many of the democrats are female ?
Options: a. 75, b. 100, c. 125, d. 175, e. 225
[EX A]: c

[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: how many seconds will a train 120 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph ?
Options: a. 17 sec, b. 21 sec, c. 25 sec, d. 27 sec, e. 29 sec
[EX A]:
d