Answer the following question.
It will cost $60 to rent a sailboat and $80 per hour to rent a ski boat. Ken rented a sailboat while Aldrich rented a ski boat. How much more did it cost Aldrich to rent the ski boat than Ken to rent a sailboat for three hours a day in two days?
Step-by-step reasoning process: Ken paid $60 x 3 = $180 to rent a sailboat for 3 hours in a day. Aldrich paid $80 x 3 = $240 to rent a ski boat in 3 hours in a day. So Aldrich paid $240 - $180 = $60 more to rent a ski boat than Ken to rent the sailboat each day. Therefore, it cost Aldrich $60 x 2 = $120 more to rent a ski boat than Ken to rent the sailboat in two days.
The answer is 120.

Answer the following question.
Peter and Kristin are to read 20 fantasy novels each in a week. Peter can read three times as fast as Kristin. If Peter reads one book in 18 hours, how long will Kristin read half of her books?
Step-by-step reasoning process: Since Peter reads three times as fast as Kristin, Kristin will take 18 * 3 = 54 hours to read one book. Kristin reads half of her books, a total of 20 / 2 = 10 books. The time Kristin will take to read half of her books is 10 * 54 = 540.
The answer is 540.

Answer the following question.
John goes to the bakery to buy rolls. They sell them for 5 dollars for a dozen. He spent 15 dollars. How many rolls did he get?
Step-by-step reasoning process: He got 15 / 5 = 3 dozen. So he bought 3 * 12 = 36 rolls.
The answer is 36.

Answer the following question.
Edna made cookies for all of her neighbors and left the cookies outside for them to take. She made 150 cookies so her 15 neighbors could get 10 cookies each. However, the neighbor who arrived last told Edna there were only 8 cookies left. Edna thinks it was Sarah who took too many cookies. If all the other neighbors took the correct amount of cookies, how many cookies did Sarah take?
Step-by-step reasoning process: Sarah and the final neighbor took the wrong amount, which means that 15 neighbors – 1 Sarah – 1 final neighbor = 13 neighbors took 10 cookies each. This is a total of 13 neighbors * 10 cookies = 130 cookies taken by the first 13 neighbors. There were only 8 cookies left, so that means the first 13 neighbors and Sarah took a total of 150 – 8 = 142 cookies. So Sarah must have taken 142 – 130 = 12 cookies.
The answer is 12.