Nancy buys 2 coffees a day. She grabs a double espresso for $3.00 every morning. In the afternoon, she grabs an iced coffee for $2.50. After 20 days, how much money has she spent on coffee? Give the rationale and then the answer.
Let's think step by step. She gets a double espresso for $3.00 every morning and an iced coffee for $2.50 in the afternoon so she spends 3 + 2.5 = $5.50 every day on coffee. After 20 days, she spends 20 * 5.5 = $110.00 on coffee.. The answer is: 110.

Jason has six fish in his aquarium. He realizes that every day the number of fish doubles. On the third day he takes out one-third of the fish. On the fifth day he takes out one-fourth of the fish. On the seventh day he adds 15 more fish. How many fish in total does he have? Give the rationale and then the answer.
Let's think step by step. Start by finding how many fish were in the aquarium on the third day 6 * 2 * 2 = 24. On day three, Jason took out one - third of the fish 24 / 3 = 8. So at the end of day three, he has 24 - 8 = 16 fish. On day five he has 16 * 2 * 2 = 64 fish, but he takes out one - fourth. So he took out 64 / 4 = 16 fishes. So at the end of day five, he has 64 - 16 = 48 fish. On day seven he has 48 * 2 * 2 = 192 fish. He adds in 15 more, so he has 192 + 15 = 207 fish in total.. The answer is: 207.

Three years ago, Bethany was twice the age of her younger sister. In 5 years, her younger sister will be 16. How old is Bethany now? Give the rationale and then the 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
Let's think step by step. First find how old Bethany's sister currently is: 16 years - 5 years = 11 years. Then find how old her sister was 3 years ago: 11 years - 3 years = 8 years. Then double that age to find how old Bethany was three years ago: 8 years * 2 = 16 years. Then add 3 years to that number to find how old Bethany is now: 16 years + 3 years = 19 years.. The answer is: 19.