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.

Q: Problem: cathy and jim begin running at the same time and they start at the same place on a straight path. cathy runs at 10 miles per hour, and jim runs at 6 miles per hour. after 18 minutes, cathy stops to stretch. if it takes cathy 27 minutes to stretch and jim continues to run during this time, how many minutes will it take cathy to catch up to jim ?
Options: a. 20.5, b. 21.5, c. 22.5, d. 23.5, e. 24.5

A: c
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Q: Problem: a 16 % stock yielding 10 % is quoted at :
Options: a. 83.33, b. 110, c. 112, d. 120, e. 160

A: e
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Q: Problem: of the total amount that jill spent on a shopping trip, excluding taxes, she spent 60 percent on clothing, 20 percent on food, and 20 percent on other items. if jill paid a 10 percent tax on the clothing, no tax on the food, and an 10 percent tax on all other items, then the total tax that she paid was what percent of the total amount that she spent, excluding taxes ?
Options: a. 10, b. 20, c. 30, d. 25, e. 15

A:
a
****