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.

Problem: what is the median of a set of consecutive integers if the sum of nth number from the beginning and nth number from the end is 110 ?
Options: a. 10, b. 25, c. 55, d. 75, e. 100
c

Problem: a car is 15 minutes late by running at a speed of 4 / 5 th of its actual speed. the actual time taken by the car to cover that distance is :
Options: a. 30 minutes, b. 1 hour, c. 2 hours, d. 3 hours, e. none of these
b

Problem: a tourist does not have to pay tax on the first $ 600 of goods he purchases in country b, but does have to pay a 11 percent tax on the portion of the total value that is in excess of $ 600. what tax must be paid by a tourist if he buys goods with a total value of $ 1720 ?
Options: a. $ 54.00, b. $ 64.80, c. $ 90.00, d. $ 100.80, e. $ 123.20

e