instruction:
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: at a florist shop on a certain day, all corsages sold for either $ 20 or $ 30. if 10 of the corsages that sold for $ 30 had instead sold for $ 20, then the store ' s revenue from corsages that day would have been reduced by 20 percent. what was the store ' s actual revenue from corsages that day ?
Options: a. $ 200, b. $ 400, c. $ 500, d. $ 800, e. $ 1000
answer:
c


question:
Problem: the arithmetic mean and standard deviation of a certain normal distribution are 14.5 and 1.7, respectively. what value is exactly 2 standard deviations less than the mean ?
Options: a. 10.5, b. 11, c. 11.1, d. 12, e. 12.5
answer:
c


question:
Problem: in a sports club with 30 members, 17 play badminton and 19 play tennis and 3 do not play either. how many members play both badminton and tennis ?
Options: a. 7, b. 8, c. 9, d. 10, e. 11
answer:

c