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: the average of first six prime numbers greater than 20 is ?
Options: a. 10, b. 20, c. 30, d. 40, e. 34
[EX A]: e

[EX Q]: Problem: two pipes a and b can fill a tank in 36 hours and 46 hours respectively. if both the pipes are opened simultaneously, how much time will be taken to fill the tank ?
Options: a. 20.195 hrs, b. 21.195 hrs, c. 22.195 hrs, d. 23.195 hrs, e. 20.495 hrs
[EX A]: a

[EX Q]: Problem: the perimeter of an isosceles right triangle is 14 + 14 sq rt 2. what is the length of the hypotenuse of the triangle ?
Options: a. 5, b. 6, c. 7, d. 8, e. 9.899
[EX A]:
e