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: what is the smallest positive integer x such that 66 - x is the cube of a positive integer
Options: a. 5, b. 7, c. 47, d. 9, e. 2
[EX A]: e

[EX Q]: Problem: 40 is subtracted from 60 % of a number, the result is 50. find the number ?
Options: a. 150, b. 330, c. 277, d. 279, e. 712
[EX A]: a

[EX Q]: Problem: a salesman sold twice as much pears in the afternoon than in the morning. if he sold $ 510 kilograms of pears that day, how many kilograms did he sell in the afternoon ?
Options: a. 120, b. 180, c. 340, d. 280, e. 320
[EX A]:
c