Question

A train 500m crosses a tunnel 0.5km between the time 10:05am and 10:10am what is the speed of train?

Answer 1

Given :

length of the train=500m=500/1000=0.5km

Length of the tunnel =0.5km

So train need to travel a distance of =length of tunnel +length of train

=0.5+0.5=1km

time=t=5m=5/60=1/12 hr

speed=?

speed =distance/time

=1/1/12

=12km/hr
∴Speed of train is 12km/hr

Answer 2

Solution :- 

Length of the train = 0.5 km

Length of the tunnel = 0.5 km

Time taken by the train = 5 minutes

= (5/60) hr

= (1/12) hr

The train has to travel 0.5 km + 0.5 km = 1 km to cross the tunnel.

So, distance travelled by the train = 1 km

Speed = Distance/Time

∴ 1 ÷ 1/12

∴ (1*12)/1

= 12 km/hr

So, speed of the train is 12 km/hr.

Answer.