You will be given a definition of a task first, then some input of the task.
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: the charge for a single room at hotel p is 20 percent less than the charge for a single room at hotel r and 10 percent less than the charge for a single room at hotel g. the charge for a single room at hotel r is what percent greater than the charge for a single room at hotel g ?
Options: a. 15 %, b. 20 %, c. 12.5 %, d. 50 %, e. 150 %
Output:
c