Question

The average speed of a train in the onward journey is 25% more than that in the return journey. The train halts for one hour on reaching the destination. The total time taken for the complete to and from journey is 17 hours, covering a distance of 800 km. The speed of the train in the onward journey is:

45 km/hr
47.5 km/hr
52 km/hr
56.25 km/hr

Answer 1

Let it's velocity in the return journey be v, then its onward velocity will be 5v/4.

400/v + 400/(5v/4) = 16
25/v + 20/v = 1
v = 45 km/hr.

Answer 2

Answer:

Step-by-step explanation:

Average speed in onward journey is 25% more than return.

So the ration of speed onward:return is 5:4.

Speed is inversely proportional to time so time taken ration is onward:return is 4:5.

Time taken for the to and fro journey is 17-1=16hrs. (1hr is for charging we should subtract that from the 17hrs).

So time taken for onward journey is (16/9)*4.

To and fro journey distance is 800. So onward journey distance is 800/2 =400km.

Therefore average speed in onward journey is

S=D/T

=400/((16/9)*4

=(25*9)/4

=56.25kmph.

Thank you