A 243 long train running at 60 km/h takes 42 seconds to cross a tunnel. The length (in m) of the tunnel is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 457
Speed = 60 km/h = 60 × 5/18 = 50/3 m/s
Length of the tunnel = x
Speed of the train = (length of the train + length of the tunnel)/time
⇒ 50/3 = (243 + x)/42
⇒ 700 - 243 = x
⇒ x = 457 m