Reasoning and answer: The amoeba will divide into 1 * 2 = 2 amoebae after 2 days. The amoeba will divide into 2 * 2 = 4 amoebae after 4 days. The amoeba will divide into 4 * 2 = 8 amoebae after 6 days. The amoeba will divide into 8 * 2 = 16 amoebae after 8 days.
The answer: 8
What was the question?
Question: An amoeba reproduces by fission, splitting itself into two separate amoebae. An amoeba reproduces every two days. How many days will it take one amoeba to divide into 16 amoebae?

Reasoning and answer: He bikes 20 * 2 = 40 miles each day for work. So he bikes 40 * 5 = 200 miles for work. That means he bikes a total of 200 + 200 = 400 miles for work. So he bikes a total of 400 / 25 = 16 hours.
The answer: 16
What was the question?
Question: Tim rides his bike back and forth to work for each of his 5 workdays. His work is 20 miles away. He also goes for a weekend bike ride of 200 miles. If he can bike at 25 mph how much time does he spend biking a week?

Reasoning and answer: Sabrina had 20 - 10 = 10 cookies left after giving 10 cookies to her brother. Sabrina's mother gave her 10 / 2 = 5 cookies. So, she had 10 + 5 = 15 cookies then. She gave 15 x 2 / 3 = 10 cookies to her sister. Therefore, she only has 15 - 10 = 5 cookies left.
The answer: 5
What was the question?
Question:
Sabrina gave 10 cookies to her brother. Her mother gave Sabrina half the number of cookies she gave her brother. Then Sabrina gave two-thirds of her cookies to her sister. If Sabrina had 20 cookies at the start, how many cookies are left with her?