Two trains, 250 metres and 150 metres long respectively, are running on parallel lines. If they are running in the same directions, the faster train crosses the slower train in 40 seconds. If they are moving in the opposite direction they pass each other in eight seconds. What is the speed of the slower train?
Answers
Given:
Length of the first train = 250 m
Length of the second train = 150 m
The time in which the faster train crosses the slower one when both the trains move in the same direction = 40 sec
The time in which the faster train crosses the slower one when both the trains move in the opposite direction = 8 sec
To find:
Speed of the slower train.
Solution:
Let the faster train run at x m/s and the slower train run at y m/s.
Since, the time in which the faster train crosses the slower one when both the trains move in the same direction is 40 sec thus,
400/ (x-y) = 40
10 = x-y - equation 1
The time in which the faster train crosses the slower one when both the trains move in the opposite direction is 8 sec, thus
400/ (x+y) = 8
50 = x+y - equation 2
On solving both the equations, we get:
x = 30 m/s and y = 20 m/s
Thus the speed of the slower train will be 20 m/s.