Question

a train 800 metres long is running at a speed of 72 km per hour if crosses a tunnel in 3 minutes then what is the length of the tunnel

Answer 1

speed= d/ t
d= s×t
=72000×3=146000m

length of train =800
length of tunnel =146000-800
= 145200m

Answer 2

TRAIN LENGTH = 800

SPEED OF TRAIN = 72 KM/HR =20 M/SEC

TIME = 3 MIN = 180 SEC

LENGTH OF THE TUNNEL = S*T-800

                                             = 3600-800

                                              = 2800 METERS