A train without stoppage travels with an average speed of 65 km/h and with stoppage, it travels with an average speed of 52 km/h. For how many minutes does the train stop on an average per hour?

Answer: Option C

Solution

Answer: Option C

Solution:

The distance of 13 km covered by the speed of 65 km/hr in time
$$\begin{array}{rl}& \to \frac{13}{65}=\frac{1}{5}\times 60=12\text{min/hr}\\ & \\ & \mathbf{Alternate}\mathbf{solution}:\\ & \left(\frac{\text{Faster speed}-\text{Slower speed}}{\text{Faster speed}}\times 60\right)\text{min/hr}\\ & =\frac{65-52}{65}\times 60\\ & =12\text{min/hr}\end{array}$$