please proofread.
time outward = d / 18
time back = d/20
total time = d/18 + d/20
total distance = 2 d
av speed = 2 d/ [d/18 + d/20]
= 2/(1/18 +1/20)
= 2/(.056+.05) = 2/.106
= 18.9 km/h
A man travels distance 18km/h from his house to an exhibition by rickshaw at km/h and return back on cycle at 20km/h find his average speed for the whole journey
1 answer