Alex is making a 4 mile trip. The first two miles were at 30 mph. At what speed must Alex cover the remaining two miles so that the average speed for the entire trip will be
Average speed = total distance / total time total distance = 4
50 m/hr = 4 m / ( 2 m / 30 m/hr + 2 m/ x m/hr)
4 / 50 - 2/30 = 2/x
x = 150 m/hr for the final 2 miles <=====Pretty fast! See what you find for the next two !