Problem & Solution –
Example.1) If a boy can walk 200m in 5 minutes.
a) Find his speed in km/h.
b) What distance he would cover in 2 hours.
c) How long he would take to cover 5 km.
Ans.) As per the given condition, a boy walks 200m in 5 minutes
So, a boy by 5 minutes covers 200 meters
200 meters
By, 1 minute he can cover = --------------
5 minutes
200 X 60
By, 1 hour = 60 minutes he can cover = ------------ = 2400 meters/h 5
Now, we would like to convert the obtained meters (m) into Kilometers (Km)
Now we have to divide 2400 meters/h by 1000 meters because as we know 1 km = 1000 meters.
2400
So, the speed of the said by in Km is = ---------- = 2.40 Km/h…...…(a)
1000
The boy can walk or can cover the distance in 2 hours
= 2.4 km/h X 2 hours = 4.80 Km………..………(b)
If the boy, covers 2.40 Km by 1 hour
1
Then, covers 1 km by = ---------
2.40
5
Then, the boy will cover 5km by = ---------- = 2.08 hours………….….(c)
2.40