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: at what rate percent per annum will a sum of money double in 6 years.
Options: a. 12.5 %, b. 13.5 %, c. 11.5 %, d. 14.5 %, e. 16.6 %
[EX A]: e

[EX Q]: Problem: of all the homes on gotham street, 1 / 3 are termite - ridden, and 4 / 7 of these are collapsing. what fraction of the homes are termite - ridden, but not collapsing ?
Options: a. 1 / 3, b. 1 / 4, c. 1 / 5, d. 1 / 6, e. 1 / 7
[EX A]: e

[EX Q]: Problem: the average marks of 30 students in a class is 100. but a student mark is wrongly noted as 70 instead of 10 then find the correct average marks ?
Options: a. a. 78, b. b. 82, c. c. 98, d. d. 91, e. e. 85
[EX A]:
c