Posted by melissa on Sunday, September 19, 2010 at 10:11am.
Richard is driving home to visit his parents125 mi of the trip are on the interstate highway where the speed limit is 65 mph Normally Richard drives at the speed limit, but today he is running late and decides to take his chances by driving at 80 mph.how many minutes will he save

physics  MathMate, Sunday, September 19, 2010 at 11:20am
Speed * time = distance
Time = distance / speed
Normal time = 125 mi/65 mph
Time at 80 mph = 125 mi/85 mph
The difference of the two times is the time saved (in hours)