Ashutosh bhardwaj
Last Activity: 6 Years ago
We know that =total distance travelled/total time taken.
Total distance be 'S'.so acc. To question
S/3 +2S/3=S.
Now for ist one third , consider time taken is 't' so now speed × time = distance so 20×t=S/3 by solving it we find that t=S/60 h and in the similiar way we find time dor second 2S/3 journey which come t=S/90 hour.
Now put these values of time in equation of average speed
=S/S/60+S/90 and then answer is 36 km/h
