A 240 m long train overtakes a man walking at 6 km/h, in the same direction, in 9seconds. How much time (in seconds) will it take to pass a 372 m long tunnel with the same speed?
Answer & explanation
Correct answer: option 2
Let speed of train = S m/sec
Speed of man = 6 km/h = 6 × \(\frac{5}{18}\) = \(\frac{5}{3}\) m/sec
Relative speed (when moves in same direction ) = (S -\(\frac{5}{3}\)) m/sec
According to question ,
240 = (S -\(\frac{5}{3}\)) × 9
85 = 3S
S = \(\frac{85}{3}\) m/sec
Total distance = 240 + 372 = 612 m
Time = \(\frac{Distance}{ Speed }\)
= \(\frac{612 × }{85}\)
= 21.6 sec