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?
Rudy first runs for 5 * 10 = <T>multiply(5, 10)=50 minutes.
Then Rudy runs for 4 * 9.5 = <T>multiply(4, 9.5)=38.0 minutes.
Rudy runs for a total length of 50 + 38 = <T>add(50, 38)=88 minutes
