Detailed Instructions: 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:Problem: in a rare coin collection, all coins are either pure gold or pure silver, and there is initially one gold coin for every 3 silver coins. with the addition of 15 more gold coins to the collection, the ratio of gold coins to silver coins is 1 to 2. based on this information, how many total coins are there now in this collection ( after the acquisition ) ?
Options: a. 124, b. 135, c. 146, d. 157, e. 168
Solution:
b