A person walks a distance from point A to B at 15 km/h, and from point B to A at 30 km/h. If he takes 3 hours to complete the journey, then what is the distance from point A to B?

30 km

Average Speed = \(\frac{2 × S1 × S2  }{S1 + S2}\)

= \(\frac{2 × 15 × 30  }{15 + 30}\)

= \(\frac{900  }{45}\)

= 20 km/h

Total distance from A to B & B to A = 20 × 3 = 60 km

Distance from A to B = \(\frac{60  }{2}\)

= 30 km