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 a no. when divided by 44, gives 432 as quotient and 0 as remainder. what will be the remainder when dividing thesame no. by 31
Options: a. 2, b. 4, c. 5, d. 7, e. 8
[EX A]: c

[EX Q]: Problem: two trains of equal are running on parallel lines in the same direction at 45 km / hr and 36 km / hr. the faster train passes the slower train in 36 sec. the length of each train is ?
Options: a. 45, b. 88, c. 66, d. 55, e. 22
[EX A]: a

[EX Q]: Problem: there are 280 doctors and nurses at a hospital. if the ratio of doctors to nurses is 5 to 9, how many nurses are at the hospital ?
Options: a. 165, b. 170, c. 175, d. 180, e. 185
[EX A]:
d