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.
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Question: Problem: when x is multiplied by 3, the result is 10 more than the result of subtracting x from 26. what is the value of x ?
Options: a. - 4, b. 9, c. 11, d. 13, e. 22

Answer: b


Question: Problem: buses a and b start from a common bus stop x. bus a begins to travel in a straight line away from bus b at a constant rate of 30 miles per hour. one hour later, bus b begins to travel in a straight line in the exact opposite direction at a constant rate of 50 miles per hour. if both buses travel indefinitely, what is the positive difference, in minutes, between the amount of time it takes bus b to cover the exact distance that bus a has covered and the amount of time it takes bus b to cover twice the distance that bus a has covered ?
Options: a. 36, b. 84, c. 132, d. 144, e. 180

Answer: b


Question: Problem: sandy bought 65 books for $ 1080 from one shop and 55 books for $ 840 from another shop. what is the average price that sandy paid per book ?
Options: a. $ 14, b. $ 16, c. $ 18, d. $ 20, e. $ 22

Answer:
b