Question

a men walking at the rate of 4km/hr crosses a bridge in 18 minutes . find the length of the bridge in metres

Answer 1

 man walking at the rate of 5 km/hr. crosses a bridge in 15 minutes. The length of the bridge (in meters) is:
[A]1000 m
[B]1250 m
[C]600 m
[D]750 m

1250 m
Speed of the man = 5 km/hr

Time taken to cross the bridge = 15 minutes
Length of the bridge = Speed  Time

Hence option [B] is the right answer.