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: mary works in a restaurant a maximum of 70 hours. for the first 20 hours, she is paid $ 8 per hour. for each overtime hour, she is paid at a rate which is 25 % higher than her regular rate. how much mary can earn in a week ?
Options: a. 600, b. 620, c. 660, d. 320, e. 400

Answer: c

Question: Problem: in a room filled with 6 people, all 6 people have exactly 1 sibling in the room. if two individuals are selected from the room at random, what is the probability that those two individuals are not siblings ?
Options: a. 3 / 5, b. 4 / 5, c. 5 / 6, d. 5 / 12, e. 7 / 12

Answer: b

Question: Problem: if n is an integer and 101 n ^ 2 is less than or equal to 6400, what is the greatest possible value of n ?
Options: a. 7, b. 8, c. 9, d. 10, e. 11

Answer:
a