Question

A train moving at 78 km/h crosses a tunnel in 45 seconds and it crosses a man moving at 6 km/h in the same direction in 15 seconds. What will be the length of the tunnel?

• A. 550 m
• B. 720 m
• C. 675 m
• D. 430 m

Answer 1

Answer:

C. 675 m

Relative Speed of the train = 78 - 6 = 72 km/h Length of train = 72 × 5/18 × 15 = 300 m Length of train + Tunnel = Speed of train × Time to cross tunnel 300 + length of tunnel = 78 × 5/18 × 45 = 975 Length of tunnel = 675 m