Question

a man walking at the rate of 5 km per hour crosses a bridge in 15 minutes the length of the bridge in metres is

Answer 1

length= distance
given speed = 5km/hr
time= 15mins = 15/60 hrs
we know speed = distance/time
5 = distance/15/60
5 = 60×distance/15
5= 4× distance
distance= 5/4
= 1.25kms or 1.25× 1000= 1250 meters is answer

Answer 2

here, we have
speed = 5 km/hr
time taken = 15 min or 15*1/60 = 1/4 hour
since we know that,
distance = speed * time = 5 *1/4 = 5/4 km
since 1 km = 1000m
therefore,
distance = 5/4 *1000 = 5 *250 = 1250 metres