A train takes 18 sec to cross a man who is standing on a platform . While it takes 35 sec to cross a 170 meter long platform . Find length of the train .
Answer & explanation
Correct answer: option 1
Let length of train = x meter
Time taken to cross a man is 18 sec . so total distance traveled is only length of train
Distance = Speed × Time
Speed = \(\frac{x}{18}\) ------ ( 1 )
Train takes 35 sec to cross a 170 meter long platform, total distance = 170 + x
Speed = \(\frac{170\;+\;x}{35}\) ---------- ( 2 )
Speed of train is same so put equation 1 equals to equation 2
\(\frac{x}{18}\) = \(\frac{170\;+\;x}{35}\)
35x = 3060 + 18x
17x = 3060 ⇒ x = 180 m
so, length of train = 180 m