Ramakant travelled from his home to friend’s house. If he covers three equal distances at a speed of 30 km/hr, 15 km/hr and 10 km/hr respec…

Let the total distance travelled by Ramakant be 3 × L.C.M. of 30, 15 and 10

= 3 × 30 = 90 km

We know that, average speed = (total distance)/(total time taken)

∴ average speed $(= \frac{{90}}{{\frac{{30}}{{30}} + \frac{{30}}{{15}} + \frac{{30}}{{10}}}})$

= 90/(1 + 2 + 3)

= 90/6 = 15 km/hr