Question

A man drives 150 kilometres to the seashore in 3 hours and 20 minutes. He returns from the shore to the starting point in 4 hours and 10 minutes. Let r be the average rate for the entire trip. Then the average rate for the trip going exceeds r, in kilometres per hour, by:

Answer 1

av speed = total distance upon total time 150 +150
3+4 =7 hrs
20+10= 0.5 hrs
7.5 hrs
av speed 300km÷7.5 hrs=40 km/hr