Question

walking and average speed of 3 kilometre per hour round cross a bridge in 7.5 minutes his friends Sachin's cross the bridge in 4.5 minutes what is Sachin speed in kilometre per hour?

Answer 1

1st we have to find total distance as
distance=speet×t in km
$d = 3 \times 7.5 \div 60$
d=0.375 km
now
speed=distance ÷time
$0.375 \div 4.5 \div 60$
=.375×60/4.5
speed= 5 kmph