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.

[Q]: Problem: an article is bought for rs. 675 and sold for rs. 900, find the gain percent ?
Options: a. 33 1 / 8 %, b. 33 9 / 3 %, c. 33 1 / 3 %, d. 93 1 / 3 %, e. 33 2 / 3 %
[A]: c


[Q]: Problem: what is the probability of getting a queen or spade from a set of cards ?
Options: a. 3 / 13, b. 4 / 13, c. 5 / 13, d. 6 / 13, e. 7 / 13
[A]: b


[Q]: Problem: x does a work in 20 days. y does the same work in 40 days. in how many days they together will do the same work ?
Options: a. 10, b. 12, c. 20, d. 30, e. 13.33
[A]:
e