# CLASS-8SPEED-TIME-DISTANCEPROBLEM & SOLUTION

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