Question

A train goes from town A to town B at a speed of $80kmp{h}^{-1}$ and comes back from town B to town A at a speed of $60kmp{h}^{-1}$. Calculate the average speed of the train.

Answer 1

Let the distance be 's' km

Average Speed $\left(v\right)=\frac{TotalDistance}{TotalTime}=\frac{2s}{\frac{s}{80}+\frac{s}{60}}$

$v=\frac{2\times 60\times 80}{60+80}=68.57km/h$