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: 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
[EX A]: e

[EX Q]: Problem: what is the area of a regular hexagon with sides 1 in. long ?
Options: a. 1.59 square inch, b. 2.59 square inch, c. 3.59 square inch, d. 4.59 square inch, e. 2.69 square inch
[EX A]: b

[EX Q]: Problem: find the number which multiplied by 15 is increased by 196.
Options: a. 14, b. 20, c. 26, d. 28, e. 27
[EX A]:
a