A train of length 442 metres crosses an electric pole in 13 seconds and crosses another train of the same length travelling in opposite direction in 17 seconds. What is the speed of the second train?

Given: 

Length of the train1 = 442 m 

Time taken to cross the pole = 13 sec

Length of the train2 = 442 m  

Time taken to cross the train2 = 17 sec

Formula Used: 

Speed = $$\frac{Distance}{Time}$$ 

Solution: 

Speed of Train1 = $$\frac{442}{13} = 34\, m/sec$$ 

Now, Train1 crosses the Train2 running in opposite direction;

Relative speed = Speed1 + Speed2 

Applying the Speed formula;

34 + Speed2 = $$\frac{442+442}{17}$$ 

Speed2 = $$52 - 34 = 18 \, m/sec$$ 

Thus, speed of second train is 18 m/sec.