Question

Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. for how many minutes does the bus stop per hour?

a. 9

Answer 1

Without stoppage, bus speed = 54 km/hr
Thus it travels 54 km in 1 hour
With stoppage, bus speed = 45 km/hr
It travels 45 km in 1 hour.
The 9 km distance difference (54-45) is due to stoppages.
Now, its actual speed is 54 km/hr (without stoppage)
Hence to cover this 9 km:
T = 9/54 = 1/6 hrs = 1/6 * 60 = 10 minutes.
So, the bus stops 10 minutes per hour.

Hope it helps.