A vehicle travels equal distances at 60km/h and 90km/h.calculate its average speed

Answer 1

formula for average speed=total distance/total time
A=[(60+90)km/h]/no time?
insufficient information

Answer 2

Let the distance for each section be x km
time for the first leg = x/60
time for the 2nd leg = x/90
total time = x/60 + x/90
= (3x+ 2x)/180 = x/36

avg speed = total distance/total time
= 2x/(x/36)
= 2x(36/x)
= 72 km/h

notice it is not the average of the two speeds.