Question

A man standing on the platform find that a train takes 3 s to pass

Answer 1

Answer:

3x3/7 seconds

Step-by-step explanation:

Let the length of both the trains = l metre(equal) speed of the first train = s1 m/s

and another's speed= s2 m/s

ATQ,

ls1=3

s1=l3......1

Again

ls2=4

s2=l4........2

Crossing time in opposite direction to each other.

=total distancetotal speed=l+ll3+l4=2l7l×12

=247 sec

=3 x 3/7 sec