distance and speed

Nanu travels at 54 km/hr excluding stoppages and at 45 km/hr including stoppages. How many minutes of stoppage is there in an hour?

Answer:

Basis : 1 hour

let distance to be covered be 54 km

so, distance covered with stoppages = 45 km

shortfall in distance covered = 54 - 45 = 9 km

time taken to cover 9 km = 9/54 = 1/6 hour

so, minutes of stoppage per hour = 60 x 1/6 = 10 mins