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: what is the median of a set of consecutive integers if the sum of nth number from the beginning and nth number from the end is 110 ?
Options: a. 10, b. 25, c. 55, d. 75, e. 100
[EX A]: c

[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: calculate the effect changes in dimension of a rectangle will have on its area, if length is increased by 40 % and its breadth is decreased by 25 % ?
Options: a. 5 % increase, b. 7 % increase, c. 6 % increase, d. 4 % increase, e. 3 % increase
[EX A]:
a