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.

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 %
e

Problem: at the wholesale store you can buy an 8 - pack of hot dogs for $ 1.55, a 20 - pack for $ 3.05, and a 250 - pack for $ 22.95. what is the greatest number of hot dogs you can buy at this store with $ 205 ?
Options: a. 1,108, b. 2,100, c. 2,140, d. 2,124, e. 2,256
c

Problem: 50 % of a number is added to 200, the result is the same number. find the number ?
Options: a. 300, b. 288, c. 400, d. 129, e. 281

c