without stoppage a train travels a distance with an average speed of 60 km/hr and with stoppage it covers the same distance with an average speed of 40 km/hr. on an average how many min per hour does the train stop during the journey.

Answer 1

let the travel time be t hrs
let the stoppage time be s hrs

without stopping, distance = 60t
with stops, distance = 40(t+s)

60t = 40t + 40s
20t = 40s
t = 2s

So for any given time, the train spends twice the time driving as it does stopping
or
in hour , the time stopping is 20 minutes and the time driving is 40 minutes.

let's take some cases to illustrate:
suppose the distance is 240 km
time without stopping = 4 hrs
time with stops = 6 hours
time spend on stops = 2 hrs, which is 1/2 of the time driving

suppose the distance is 600 km
time without stops = 10 hours
time with stops = 15 hours
time spent on stops = 5 hours, which is 1/2 of the time driving