Find the length of a train, if ii completely crosses two bridges of lengths 600 m and 300 min 80 seconds and 60 seconds, respectively.
Answer & explanation
Correct answer: option 3
Let the length of train = D meter
Speed = \(\frac{DIstance}{Time}\)
Distance covered by train in 120 sec = (600 + D)
Speed = \(\frac{( 600 + D )}{120}\) -------(1)
Distance covered by train in 80 sec = (300 + D)
Speed = \(\frac{( 600 + D )}{80}\) --------(2)
Equating equation (1) and (2)
\(\frac{( 600 + D )}{120}\) = \(\frac{( 600 + D )}{80}\)
1200 + 2D = 900 + 3D
D = 300 m
So , Length of train is 300 m