There are 2 trains P and Q moving in same direction. They are of equal length and cross a stationary pole in 5 seconds and 6 seconds respectively. In how much time would they cross each other?
Answer with explanationAnswer: Option A
Length of the train = l meter.
Speed of the two trains are l/5 and l/6.
Total distance = 2l.
In same direction Relative speed is (l/5 – l/6).
= l/5 – l/6 = l/30.
Required Time = Distance/Speed.
= 2l/(l/30) = 60 seconds.
Formula = 2(Product of time taken)/Difference of time taken.
= 2(6 * 5)/(6 – 5) = 2 * 30 = 60 seconds.