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: if a man lost 8 % by selling oranges at the rate of 25 a rupee at how many a rupee must he sell them to gain 25 % ?
Options: a. 20, b. 15, c. 18.4, d. 20, e. 12.8

Answer: c


Question: Problem: the cash realised on selling a 14 % stock is rs. 109.25, brokerage being 1 / 4 % is ?
Options: a. 366, b. 106, c. 102, d. 109, e. 122

Answer: d


Question: Problem: two trains leave a station traveling the same direction. train a leaves the station traveling at a constant speed of 60 mph, and train b leaves the station traveling at a constant speed of 80 mph. if both trains maintain constant speeds, in how many minutes will train b overtake train a if train a left 40 minutes prior to train b ?
Options: a. 90, b. 100, c. 110, d. 120, e. 130

Answer:
d