A train travelling with a speed of 60 km/hr catches another train travelling in the same direction and then leaves it 120m behind in 18 seconds. The speed of the second train is

Given speed of the first train = 60 km/hr = 60 x 5/18 = 50/3 m/s

Let the speed of the second train = x m/s

Then, the difference in the speed is given by

$\frac{50}{3} - x = \frac{120}{18}$

=> x = 10 m/s

=> 10 x 18/5 = 36 km/hr