A train 108 m long moving at a speed of 50 km/hr crosses a train 112 m long coming from opposite direction in 6 seconds. The speed of the second train is:

Step 1: Convert the speed of the first train to m/s

Speed = 50 km/hr = (50 × 1000) / 3600 = 13.89 m/s

Step 2: Let the speed of the second train be x km/hr

Then, speed in m/s = (x × 1000) / 3600 = x × (5/18) m/s

Step 3: Total length to be covered when trains cross each other = 108 + 112 = 220 m

Relative speed = 13.89 + (5x/18) m/s

Time = Distance / Relative Speed

6 = 220 / (13.89 + (5x/18))

Step 4: Solve the equation

13.89 + (5x / 18) = 220 / 6 = 36.67

(5x / 18) = 36.67 - 13.89 = 22.78

Multiply both sides by 18:
5x = 410.04
x = 410.04 / 5 = 82.01

Answer: 82 km/hr

The speed of the second train is approximately 82 km/hr.

This is a classic time–distance–speed problem involving relative speed when two objects move towards each other. Such problems are common in quantitative aptitude sections of exams like SSC, Bank PO, and Railway Recruitment.