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 perimeter of an isosceles right triangle is 12 + 12 sq rt 2. what is the length of the hypotenuse of the triangle ?
Options: ['a. 5', 'b. 6', 'c. 7', 'd. 8.485', 'e. 8']
[EX A]: d

[EX Q]: Problem: the circumference of the front wheel of a cart is 30 ft long and that of the back wheel is 32 ft long. what is the distance traveled by the cart, when the front wheel has done five more revolutions than the rear wheel ?
Options: a. 20 ft, b. 25 ft, c. 750 ft, d. 900 ft, e. 2400 ft
[EX A]: e

[EX Q]: Problem: a dealer purchases 15 articles for rs. 25 and sells 12 articles for rs. 32. find the profit percentage ?
Options: a. 80 %, b. 50 %, c. 59 %, d. 40 %, e. 60 %
[EX A]:
e