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 8 men or 12 women can do a piece of work in 30 days, in how many days can the same work be done by 6 men and 11 women ?
Options: a. 10 days, b. 11 days, c. 13 days, d. 15 days, e. 18 days
[EX A]: e

[EX Q]: Problem: what will be the percentage increase in the area of the cube ' s surface if each of the cube ' s edges grows by 40 % ?
Options: a. 95 %, b. 90 %, c. 85 %, d. 96 %, e. 25 %
[EX A]: d

[EX Q]: Problem: what is the maximum number of pieces of birthday cake of size 4 ” by 4 ” that can be cut from a cake 20 ” by 20 ” ?
Options: a. 5, b. 10, c. 16, d. 20, e. 25
[EX A]:
e