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: in what time will a railway train 50 m long moving at the rate of 36 kmph pass a telegraph post on its way ?
Options: a. 5 sec, b. 4 sec, c. 3 sec, d. 6 sec, e. 1 sec
[EX A]: a

[EX Q]: Problem: a bag contains 10 red jellybeans and 10 blue jellybeans. if 3 jellybeans are removed one at a time, at random and are not replaced, what is the probability e that all 3 jellybeans removed from the bag are blue ?
Options: a. 9 / 100, b. 2 / 19, c. 1 / 8, d. 3 / 20, e. 3 / 10
[EX A]: b

[EX Q]: Problem: a sum of money is put out at compound interest for 2 years at 20 %. it would fetch rs. 723 more if the interest were payable half - yearly, then it were pay able yearly. find the sum.
Options: a. 22200, b. 21897, c. 28799, d. 30000, e. 32782
[EX A]:
d