[Question]Brittany got a 78 on her first test. After her second test, her average rose to an 81. What grade did she get on her second test?
[Answer]First multiply her average grade by the number of tests she took to find the total number of points she scored: 81 points * 2 = 162 points. Then subtract the number of points she scored on her first exam to find how many points she scored on her second exam: 162 points - 78 points = 84 points. The answer is 84.
Q: Jenn is saving up money to buy a bike. She has 5 jars full of quarters. Each jar can hold 160 quarters. If the bike costs 180 dollars, how much money will she have left over after buying it?
A: Jenn has 5 * 160 = 800 quarters. The quarters are worth 800 * 0.25 = 200 dollars. After buying the bike she will have 200 - 180 = 20 dollars left. The answer is 20.
Question: Kirsty collects small models of animals. The last time she bought some, each one cost $0.45. She saves enough to buy 30 models, but when she goes to the shop, she finds out that the price had increased to $0.50. How many models can she buy now?
Answer: Kirsty has 0.45 × 30 = $13.50 to spare to buy her models. She can only buy 13.50 ÷ 0.50 = 27 models as the price of each individual model has increased. The answer is 27.
[Question]Lauren sent 65 pieces of mail on Monday, 10 more pieces of mail on Tuesday than on Monday, 5 fewer on Wednesday than on Tuesday, and 15 more pieces of mail on Thursday than on Wednesday. How many pieces of mail did Lauren send?
[Answer]Lauren sent 65 + 10 = 75 pieces of mail on Tuesday. He sent 75 - 5 = 70 pieces of mail on Wednesday. And sent 70 + 15 = 85 pieces of mail on Thursday. Therefore, he sent 65 + 75 + 70 + 85 = 295 pieces of mail. The answer is 295.
Q: Jackie loves to climb trees. She climbed a 1000 foot tall tree. Then she climbed 2 trees that were half as tall as the first tree. She finished by climbing a tree that was 200 feet taller than her first tree. What was the average height of the trees that Jackie climbed?
A: Jackie climbed 2 trees that were 1 / 2 * 1000 feet = 500 feet tall each. Jackie climbed a final tree that was 1000 + 200 feet = 1200 feet. In total, the 4 trees Jackie climbed were 1000 feet + 500 feet + 500 feet + 1200 feet = 3200 feet. The average height tree that Jackie climbed was 3200 feet / 4 trees = 800 feet tall. The answer is 800.
Question: Tommy is making 12 loaves of bread. He needs 4 pounds of flour per loaf. A 10-pound bag of flour costs $10 and a 12-pound bag costs $13. When he is done making his bread, he has no use for flour and so he will throw away whatever is left. How much does he spend on flour if he buys the cheapest flour to get enough?
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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He needs 48 pounds of flour because 12 x 4 = 48. He needs 4.8 bags of 10 pound bags because 48 / 10 = 4.8. He therefore needs to buy 5 bags of flour because 4 < 4.8 < 5. He spends $50 if he buys this flour because 5 x 10 = 50. He needs 4 bags of the 12 - pound flour because 48 / 12 = 4. He would spend $52 on the 12 - pound bags because 4 x 13 = 52. He spends $50 if he buys the cheapest flour because 50 < 52. The answer is 50.