Q: Bert, Ernie, and Peggy collect stamps. Bert has four times as many stamps as Ernie, but Ernie has three times as many stamps as Peggy. If Peggy currently has 75 stamps in her collection, how many stamps does she need to add to her collection to have a collection as large as Bert's collection?
A: Ernie has three times as many stamps as Peggy, or 3 * 75 = 225 stamps. Bert has 4 times as many stamps as Ernie, or 4 * 225 = 900 stamps. Thus, Peggy would need 900 - 75 = 825 more stamps to have a collection as large as Bert's. The answer is 825.

Q: Rudy runs 5 miles at a rate of 10 minutes per mile. Later he runs 4 miles at a rate of 9.5 minutes per mile. What is the total length of time that Rudy runs?
A: Rudy first runs for 5 * 10 = 50 minutes. Then Rudy runs for 4 * 9.5 = 38 minutes. Rudy runs for a total length of 50 + 38 = 88 minutes. The answer is 88.

Q: Earl started delivering newspapers on the first floor of a condominium building. He then went up 5 floors then went down 2 floors. He again went up 7 floors and found that he is 9 floors away from the top of the building. How many floors does the building have?
A:
Earl was on the 1 + 5 = 6th floor after going up 5 floors. When he went down 2 floors, he was on the 6 - 2 = 4th floor. Since he went up 7 floors, he was then on the 4 + 7 = 11th floor. Since he is 9 floors away from the top of the building, therefore the building has 11 + 9 = 20 floors. The answer is 20.