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: to deliver an order on time, a company has to make 25 parts a day. after making 25 parts per day for 3 days, the company started to produce 5 more parts per day, and by the last day of work 100 more parts than planned were produced. find how many parts the company made and how many days this took.
Options: a. 600, b. 500, c. 575, d. 655, e. 675
[EX A]: e

[EX Q]: Problem: if each participant of a chess tournament plays exactly one game with each of the remaining participants, then 276 games will be played during the tournament. find the number of participants.
Options: a. 20, b. 22, c. 24, d. 26, e. 28
[EX A]: c

[EX Q]: Problem: of the 200 stamps in a collection, 90 are foreign and 80 are more than 10 years old. if 20 stamps are both foreign and more than 10 years old, how many stamps are neither foreign nor more than 10 years old ?
Options: a. 50, b. 80, c. 100, d. 130, e. 150
[EX A]:
a