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: rajani has to read a book of 445 pages. she has already read the first 157 pages of the book and if she reads 24 pages of the book everyday then how long will she take now to complete the book ?
Options: a. 25 days, b. 20 days, c. 46 days, d. 21 days, e. none of these
[EX A]: e

[EX Q]: Problem: if the simple interest on a certain sum of money for 6 years is one – fifth of the sum, then the rate of interest per annum is
Options: a. 3.3 %, b. 7.2 %, c. 6.1 %, d. 5.0 %, e. 3.1 %
[EX A]: a

[EX Q]: Problem: a bag contains 5 green and 8 white balls. if two balls are drawn simultaneously, the probability that both are of the same colour is
Options: a. 8 / 15, b. 2 / 5, c. 3 / 5, d. 11 / 15, e. 19 / 39
[EX A]:
e