A body covers one – third of its journey with speed ‘u’ next one – third with speed ‘v’ and the last one – third with speed ‘w’ calculate the average speed of the body during the entire journey.

Let total distance = x              speed=distancetime time=distancespeed  Total time taken=x3u+x3v+x3w total time taken=xvw+uw+uv3uvw---(1)  Average speed =Vav=total  disatnce  travelledtotal  time  taken---(2) substitute equation (1) in (2)Vav=xxvw+uw+uv3uvw     Average speed=3uvwvw+uw+uv