Question

If a man travels at $10$ km/hr from $A$ to $B$ and again at $15$ km/hr from $B$ to $A$. Find the average speed of man for complete journey.

Answer 1

Avg. speed = $\frac{2\times 10\times 15}{10+15}=\frac{2\times 10\times 15}{25}$ = 12 km/hr