Question

Ram goes from point A to B by auto at the speed of 20 km/hr and comes back from B to A in a cab at a speed of 80 km/hr. Find his average speed.

• A. 32 km/hr
• B. 50 km/hr
• C. 0 km/hr
• D. 100 km/hr

Answer 1

The correct option is A

32 km/hr

Let's assume the distance between the point A and B is'd' km

Now he went with the speed 20 km/hr

So time = $\frac{d}{20}$ $\therefore (s=\frac{d}{t})$

He comes back with the speed 80 km/hr

So time = $\frac{d}{80}$ $\therefore (s=\frac{d}{t})$

So average speed = $\frac{Totaldistance}{TotalTime}$

= $\frac{d+d}{\frac{d}{20}+\frac{d}{20}}$

= $\frac{2}{\frac{1}{20}+\frac{1}{20}}=32km/hr$