A train can cross a 1200-metre-long bridge completely in 16 seconds. It can cross a 1600-metre-long bridge completely in 20 seconds. What is the speed of the train?
Answer & explanation
Correct answer: option 1
Let length of train = l meter
According to question ,
\(\frac{1200 + l}{16}\) = \(\frac{1600 + l}{20}\)
\(\frac{1200 + l}{4}\) = \(\frac{1600 + l}{5}\)
6000 + 5l = 6400 + 4l
l = 400 m
Length of train is 400 m .
Speed of train = \(\frac{1200 +400}{16}\) = 100 m/sec
100 × \(\frac{18}{5}\) = 360 km/h