A 320 m long train completely crosses a 240 m long train, coming from the opposite direction, in y seconds. If the first train is travelling at the speed of 44 km/h and the second train is travelling at 56.8 km/h, then what is the value of y?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 20.
Given that, Length of train 1 = 320 m
Length of train 2 = 240 m
Speed of train 1 = 44 km/h
Speed of train 2 = 56.8 km/h
When two trains are running in opposite directions, the relative speed of the trains is equal to the sum of the individual speeds of the train.
According to the given question,
Relative speed of trains = 44 + 56.8
⇒ 100.8 km/h
Relative speed in m/sec = 100.8
⇒ 28 m/sec
Distance = Speed × Time
Now, time =
⇒ y =
⇒ y = 20 sec
Hence the value of y(in seconds) is 20.