Question

Two goods trains each 390m long are running in same
direction on parallel tracks. Their speeds are 42 km/hr
and 36 km/hr. respectively. Find the time taken by the
faster train to cross the driver of the slower one?​

Answer 1

Answer:

7.8 minute

Step-by-step explanation:

Say Train A is running with 42 km/hr

and Train B is running with 36 km/hr

Length of train=390 m=0.39 km

As shown in the figure Train has to pass 390+390=780 m

Relative speed of trains=42-36=6 km/hr=6000 m/hr=6000/60=100 m/min

Thus time taken=780/100 min

=78/10=7.8 minute