A man walks from point A to B at a speed of 15km/h, but comes back from point B to A at a speed of 25km/h. Find his average speed.

When a person travels equal distances at two different speeds, x and y, the average speed is given by the formula:
Average Speed=
x+y
2xy
​

Given:

Speed from A to B (x) = 15km/h

Speed from B to A (y) = 25km/h

Average Speed=
15+25
2×15×25
​

Average Speed=
40
750
​
=18.75km/h