A train takes one minute to cross a tunnel of length 700 meter at the speed of 72 km/hr. Find length of the train.
Answer & explanation
Correct answer: option 3
Length of train = 700 m
Length of tunnel = X (let)
Time taken to cross the tunnel = 1 minute = 60 sec.
Speed = 72 km/hr
= \(\frac{72\;×\;5}{18}\) m/sec
To cross the tunnel train needs to travel = Length of train + length of tunnel = 700 +X
Now,
distance = speed × Time
20 × 60 = 700 + X
X = 1200 - 700 = 500 m
Length of tunnel = 500 m