Answer the following question.
Keanu was surfing towards the shore at a speed of 20 miles per hour. A shark was swimming alongside him, riding the same wave, when it doubled its speed and moved away from Keanu. There was a pilot fish swimming alongside Keanu and the shark, and when the shark increased its speed, the pilot fish also increased its speed and moved away from Keanu, but only increasing its speed by half as much as the shark had increased its speed by. What speed, in miles per hour, was the pilot fish swimming when it moved away from Keanu?
Step-by-step reasoning process: The shark went from 20 miles per hour to a speed of 2 * 20 = 40 miles per hour. The shark increased its speed by 40 - 20 = 20 miles per hour. Half of the shark's increase in speed is 20 / 2 = 10 miles per hour. Thus the pilot fish had increased its speed to 20 + 10 = 30 miles per hour.
The answer is 30.

Answer the following question.
It takes David 10 minutes to wash 4 windows. David's house has 64 windows. How many minutes will it take David to wash all of the windows?
Step-by-step reasoning process: It takes 10 minutes to wash 4 windows and he has 64 windows so that breaks down to 64 / 4 = 16 units. It takes 10 minutes to wash a unit of windows and he has 16 units so 10 * 16 = 160 minutes.
The answer is 160.

Answer the following question.
A library has a collection of 100 historical novels arranged on a shelf. 5 people borrow 2 books each from the shelf on a particular day, and 20 more books are borrowed from the shelf on the second day. How many books are remaining on the shelf after the second day?
Step-by-step reasoning process: Five people borrowed 5 people * 2 books / person = 10 books on the first day. After the second day, the total number of borrowed books increased to 10 books + 20 books = 30 books. The total number of books on the shelf after the second day is 100 books - 30 books = 70 books.
The answer is 70.

Answer the following question.
A movie that's 1.5 hours long is being replayed 6 times in one movie theater each day. There is a 20-minute advertisement before the start of the movie. How long, in hours, does the movie theater operate each day?
Step-by-step reasoning process: The movie that is being replayed 6 times takes 1.5 x 6 = 9 hours. The advertisements before the start of the movie take 20 x 6 = 120 minutes in all. One hundred twenty minutes is equal to 120 / 60 = 2 hours. Thus, the movie theater operates for 9 + 2 = 11 hours each day.
The answer is 11.