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: if 80 percent of a class answered the first question on a certain test correctly, 55 percent answered the second question on the test correctly, and 20 percent answered neither of the questions correctly, what percent answered both correctly ?
Options: a. 10 %, b. ( 8 ) 20 %, c. 30 %, d. 50 %, e. 55 %

Answer: e


Question: Problem: 108 ã — 108 + 92 ã — 92 = ?
Options: a. 20120, b. 11500, c. 20128, d. 20660, e. 20228

Answer: c


Question: Problem: after decreasing 24 % in the price of an article costs rs. 684. find the actual cost of an article ?
Options: a. 218, b. 777, c. 900, d. 2688, e. 1991

Answer:
c