Question: The vending machine fails to drop a snack when it’s purchased one in six times. One in ten times, it will accidentally drop two snacks. The rest of the time, it drops the purchased snack. If thirty people have used the vending machine once each to purchase a snack, how many snacks has the vending machine dropped?
Answer: The vending machine has been used 30 times, so it has failed to drop a snack 30 / 6 = 5 times. The vending machine has dropped 2 snacks 30 / 10 = 3 times. It has operated normally and dropped 1 snack 30 - 5 - 3 = 22 times. Thus, the vending machine has dropped 22 + 3 * 2 = 22 + 6 = 28 snacks in thirty uses. The answer is 28.
[Question]John goes to the bakery to buy rolls. They sell them for 5 dollars for a dozen. He spent 15 dollars. How many rolls did he get?
[Answer]He got 15 / 5 = 3 dozen. So he bought 3 * 12 = 36 rolls. The answer is 36.
Q: Kyle goes to basketball practice every day for 2 hours. At practice he spends half of the time shooting and the rest of the time running and weight lifting. If he runs for twice the time he spends weightlifting, how much time in minutes does he spend lifting weight?
A: Half of the 2 - hour practice is for running and weightlifting, so the time for running and weight lifting is 1 / 2 * 2 hours = 1 hour. If the time he lifts weights is x, then the time he runs is 2x. So the time for running and weight lifting is x + 2x = 3x = 1 hour. Thus 3x = 60 minutes. Thus x = 60 / 3 = 20 minutes spent weight lifting. The answer is 20.
Question: Each class uses 200 sheets of paper per day. The school uses a total of 9000 sheets of paper every week. If there are 5 days of school days, how many classes are there in the school?
Answer: Each class uses 200 x 5 = 1000 sheets of paper in a week. Thus, there are 9000 / 1000 = 9 classes in the school. The answer is 9.
[Question]Emma bought 3 dozens of macarons in addition to her 10 pieces of macarons for a party. If 15 pieces of macarons are left over, how many pieces of macarons were eaten?
[Answer]Three dozens of macarons are equal to 3 x 12 = 36 pieces of macarons. So Emma has a total of 36 + 10 = 46 pieces of macarons for the party. Therefore, 46 - 15 = 31 pieces of macarons were eaten. The answer is 31.
[Question]Rudy runs 5 miles at a rate of 10 minutes per mile. Later he runs 4 miles at a rate of 9.5 minutes per mile. What is the total length of time that Rudy runs?
[Answer]

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
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Rudy first runs for 5 * 10 = 50 minutes. Then Rudy runs for 4 * 9.5 = 38 minutes. Rudy runs for a total length of 50 + 38 = 88 minutes. The answer is 88.