Question: Mary and her two friends agreed to evenly pay for the cost of 2 pounds of chicken. Mary's mother went to the grocery and bought the 2-pound chicken, 3 pounds of beef that cost $4 per pound, and a liter of oil that costs $1. If Mary's mother paid a total of $16 for the grocery, how much should Mary and her two friends pay each for the chicken?
Answer: Three pounds of beef cost $4 x 3 = $12. Mary's mother paid $12 + $1 = $13 for the beef and oil. Hence, the 2 - pound chicken cost $16 - $13 = $3. There are 1 (Mary) + 2 friends = 3 people who will split the $3 cost. Therefore, each of them will pay $3 / 3 = $1. The answer is 1.

Question: Katrina saw an ad that said if she signed up for her local recycling program, she could earn $5.00. When she signed up, they told her for every friend that she referred, the friend would receive $5.00 and she would receive another $5.00 per friend. That day, she had 5 friends sign up and another 7 friends by the end of the week. How much money in total did she and her friends make?
Answer: She signed up 5 friends, then an additional 7 for a total of 5 + 7 = 12 friends. Each friend received $5 so 12 * 5 = $60.00. And she received $5 for each friend so 12 * 5 = $60.00. Her initial reward was $5 and her friends made $60 for signing up and she received $60 when they signed up for a total of 5 + 60 + 60 = $125.00. The answer is 125.

Question: The teacher agrees to order pizza for the class. For every student in the class, she will buy 2 pieces of cheese and 1 piece of onion and they will eat exactly that amount. A large pizza has 18 slices. She orders 6 total pizzas and there are 8 pieces of cheese and 4 pieces of onion leftover. How many students are in the class?
Answer: Cheese pizzas are 2 / 3 of the pizza's purchased because 2 / (2 + 1) = 2 / 3. She buys 4 cheese pizzas because 6 x (2 / 3) = 4. These give her 72 pieces of cheese pizza because 4 x 18 = 72. The students at 64 pieces of cheese because 72 - 8 = 64. There are 32 students in her class because 64 / 2 = 32. The answer is 32.

Question: A library cabinet houses five ancient scrolls. The first scroll is 4080 years old. If each scroll is older than the last by half as many years as the last scroll’s age, how old is the fifth scroll?
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.
user
The second scroll is 4080 + 4080 / 2 = 4000 + 2040 = 6120 years old. The third scroll is 6120 + 6120 / 2 = 6120 + 3060 = 9180 years old. The fourth scroll is 9180 + 9180 / 2 = 9180 + 4590 = 13770 years old. The fifth scroll is 13770 + 13770 / 2 = 13770 + 6885 = 20655 years old. The answer is 20655.