A train takes 1 minute to cross a stationary pole. How much time (in seconds) will it take to cross a bridge whose length is twice that of the train?
Answer & explanation
Correct answer: option 4
Let the length of train be D
Speed of train = \(\frac{Distance}{Time}\)
Distance = length of train
= \(\frac{D}{60}\)
According to question ,
Length of the bridge = 2D
Now , Total distance = 2D + D
Speed of train = \(\frac{3D}{Time}\)
As , Speed is same in both the cases .
\(\frac{D}{60}\) = \(\frac{3D}{Time}\)
Time = 60 × 3 = 180 seconds
So , Train will take 180 seconds to cross the bridge.