[Question]There are 10 students in a class. The average age of 9 of them is 8 years. By how many years will this average increase if the tenth student is (quite strangely) 28 years old?
[Answer]9 students have an average age of 8 years so the sum of their ages is 9 * 8 = 72 years. A tenth student who is 28 years old will make the sum 72 + 28 = 100 years. The new average age will be 100 / 10 = 10 years. This is 10 - 8 = 2 years higher than the previous average. The answer is 2.
Q: In a race, there are eight runners. The first five runners finish the race in 8 hours, while the rest of the runners finish the race 2 hours later. Calculate the total time the eight runners took to finish the race.
A: The first five runners took a combined total of 5 * 8 = 40 hours to finish the race. The number of runners who finished the race 2 hours later after the first five is 8 - 5 = 3. The 3 runners who finished the race 2 hours later took a total of 8 + 2 = 10 hours to run the race. Together, the three runners who finished the race in 10 hours took a total of 10 * 3 = 30 hours. All eight runners took 30 + 40 = 70 hours altogether to finish the race. The answer is 70.
Question: Jenny is working on a school project. She spends 10 hours doing research for the project and 2 hours writing a proposal. If she has 20 hours total to work on the project, how many hours does she have left to write her report?
Answer: So far, Jenny has spent 10 + 2 = 12 hours on the project. Thus, she has 20 - 12 = 8 hours to write her report. The answer is 8.
[Question]When Jeffrey walks, for every three steps forward, he takes two steps backwards. Therefore, if the distance between the house and the mailbox is 66 steps, what is the total number of steps Jeffrey takes when he goes from the house to the mailbox?
[Answer]For every 3 steps forward, he adds 2 more backwards so each 'step' gained costs 5 actual steps. 66 steps distance * 5 steps moved = 330 steps total. The answer is 330.
Q: Jace drives 60 miles per hour. If Jace drives for 4 hours straight, take a 30-minute break, and then drives for another 9 hours straight, how many miles will he travel?
A: Jace drives a total of 4 + 9 = 13 hours. Jace will travel 60 * 13 = 780 miles. The answer is 780.
Question: Elena has 8 lilies and 5 tulips in her garden. Each lily has 6 petals. Each tulip has 3 petals. How many flower petals are in Elena’s garden?
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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Elena has 8 * 6 = 48 lily petals. Elena has 5 * 3 = 15 tulip petals. Elena has a total of 48 + 15 = 63 petals. The answer is 63.