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.
Input: Problem: darcy lives 1.5 miles from work. she can walk to work at a constant rate of 3 miles per hour, or she can ride the train to work at a constant rate of 20 miles per hour. if she rides the train, there is an additional x minutes spent walking to the nearest train station, waiting for the train, and walking from the final train station to her work. if it takes darcy a total of 10 more minutes to commute to work by walking than it takes her to commute to work by riding the train, what is the value of x ?
Options: a. 10.5, b. 15, c. 15.5, d. 30, e. 60
Output:
c