Two trains having lengths of 210 m and 440 m are running at speeds of 60 km/h and 90 km/h, respectively, in the same direction. The time taken (in minutes) by the faster train, coming from behind, to completely cross the other train is:

Correct option is A

Given:
Length of first train = 210 m
Length of second train = 440 m
Speed of slower train = 60 km/h
Speed of faster train = 90 km/h
Both trains are running in the same direction
Formula Used:
Relative Speed (same direction) = Difference of speeds
Time = Total distance / Relative speed
Solution:
Total distance to be covered = 210 + 440 = 650 m 
Relative speed = 90 − 60 = 30 km/h 
Convert km/h into m/s = $$30 \times \frac{5}{18} = \frac{25}{3}$$​ m/s
Time taken to cross completely =$$650 \div \left(\frac{25}{3}\right) = \frac{650 \times 3}{25} = 78$$​seconds
Convert seconds into minutes=$$\frac{ 78}{ 60}$$​= 1.3 minutes