Both trains running in the opposite direction
Both trains cross the man in 48 seconds and 38 seconds
Speed = Distance/Time
Relative speed = when train in opposite direction = (x + y)m/s
Let the speed of trains be x m/s and y m/s respectively,
Length of the first train = speed × time = 48x
Length of the second train = speed × time = 38y
(48x + 38y)/(x + y) = 42
⇒ 48x + 38y = 42x + 42y
⇒ 6x = 4y
⇒ x/y = 2/3
∴ The ratio of the speed of the trains is 2 : 3
Hence, the correct answer is 2 : 3.