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?
A550 m
B720 m
C675 m
D430 m
Answer:
C. 675 m
Read Explanation:
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