Question

A car travels 40km at uniform speed of 60 km/h and next 30 km at uniform speed 60km/h. Find the average speed?

Answer 1

 Average Speed = Total Distance / Total Time
Speed = Distance / Time
Time = Distance / Speed
 total distance =  40 + 30 = 70

time 1 = 40/60 = 0.666666667

time 2 =  30/60 = 0.5

total time = 1.166666667 
average speed = 70/1.166666667  =59.999999983