A cheetah that is running 90 feet per second is 120 feet behind an antelope that is running 60 feet per second. How long will it take the cheetah to catch up to the antelope?
Note that, every second, the cheetah closes the gap between himself (or herself) and the antelope by (90 - 60) =
30 ft
So....the number of seconds to catch up is [ 120 / 30 ] = 4 seconds
+48 
