Question

A train 100 meters long takes 6 seconds to cross a man walking at 5km/h in a direction opposite
to that of the train. The speed of the train is:
(A) 50km/h
(B) 55km/h
(C) 57km/h
(D) 60km/h​

Answer 1

Answer:

option b 55 km/hr is correct

Answer 2

Answer:

Let the speed of train is v km/h

Then the relative speed =v-man's speed.

Here the man moves opposite direction with train so the man's spped in negative in sign.

So, relative speed is=v-(-5)=(v+5) km/h

Again the train cross 100 m on 6 second with the relative speed.

So relative speed=100/6 m/s

=100*3600/(1000*6) km/h

=60 km/h

So, v+5=60

Or, v=55

Thus the speed of the train is 55km/h