A truck covers three equal distances of 100 km at the speed of 200 km/hr, 300 km/hr and 600 km/hr, Find the average speed of the truck for the whole journey.

300 km/h

Distance = Speed × Time

Time 1 = \(\frac{100}{200}\) = \(\frac{1}{2}\) hours

Time 2 = \(\frac{100}{300}\) = \(\frac{1}{3}\) hours

Time 3 = \(\frac{100}{600}\) = \(\frac{1}{6}\) hours

Average speed = \(\frac{100 + 100 + 100}{1/2 + 1/3 + 1/6}\)

= 300 km/h