Question

what is the length of the bridge which a man running 15 km/hours can cross in 5 min?

Answer 1

let the speed is=X
s=d\t
x=15 \ 5
=3

Answer 2

See mate while solving these questions you need to be careful about the units of each given value now answering your question we get:

Speed=15*5/18=4.1666m/sec

time=5*60=300 seconds

Distance=speed*time

Putting the values we get:

Distance=4.16*300

distance=1238 m

distance=1.23 km

HOPE YOU GOT YOUR ANSWER! :))