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: the average age of 17 persons in a office is 15 years. out of these, the average age of 5 of them is 14 years and that of the other 9 persons is 16 years. the age of the 15 th person is ?
Options: a. 39, b. 41, c. 45, d. 42, e. 50
[EX A]: b

[EX Q]: Problem: a student took 5 papers in an examination, where the full marks were the same for each paper. his marks in these papers were in the proportion of 6: 7: 8: 9: 10. in all papers together, the candidate obtained 60 % of the total marks then, the number of papers in which he got more than 50 % marks is
Options: a. 1, b. 3, c. 4, d. 5, e. 7
[EX A]: c

[EX Q]: Problem: car dealership x, the total profit from sales increased by 8 percent over the previous years, while the number of cars sold decreased by 8 percent over the previous years. approximately what was the average percent increase in profit per car over the previous year.
Options: a. 17.39 %, b. 20 %, c. 22 %, d. 23 %, e. 25 %
[EX A]:
a