A train of length 300 metres crosses a tree in 20 seconds and crosses another train of the same length travelling in opposite direction in 25 seconds. What is the speed of the second train?
Answer & explanation
Correct answer: option 4
A trains crossed a tree i.e. its length in 20 sec .
Speed = \(\frac{Distance }{Time}\)
= \(\frac{300 }{20}\) = 15 m/sec
1st train crosses another train of same length moving in opposite direction in 25 sec
Let speed of 2nd train is X km/h
Relative speed = X + 15
Total distance = 300 + 300 = 600 m
Speed = \(\frac{600 }{25}\)
= 24m/sec
Now ,
X + 15 = 24
X = 9 m/sec
So , Speed of 2nd train is 9 m/sec