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.
--------
Question: 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 %

Answer: e


Question: Problem: what is the value of n if the sum of the consecutive odd intergers r from 1 to n equals 169 ?
Options: a. 47, b. 25, c. 37, d. 33, e. 29

Answer: b


Question: Problem: the bankers discount of a certain sum of money is rs. 18 and the true discount on the same sum for the same time is rs. 15. the sum due is :
Options: a. 89, b. 90, c. 91, d. 92, e. 93

Answer:
b