Revision Chapter 4 - Rates & Proportion

What is Proportion?

Determine whether the following pair of quantities is in proportion or not.

Q1: 48 : 60 and 32 : 40

•  $\frac{48\div12}{60\div12}\ =\ \frac{4}{5}$  

•  $\frac{32\div8}{40\div8}=\frac{4}{5}$  

• Therefore, 48:60 and 32: 40 is in proportion.

Multiple Select

(a) Determine whether it is in proportion or not

26 : 10 and 65: 25

Multiple Select

(b) Determine whether it is in proportion or not

36 : 54 and 22: 33

Multiple Select

(c) Determine whether it is in proportion or not

27 : 15 and 18: 12

Next let's look at rates?

Rate involves 2 quantities

Determine the 2 quantities involved as follows:

• The rate of change of distance is 12 m s^-1

• The rate of change of force with respect to area is 5 N m^-2

Convert the unit of rate stated in brackets

8 200 kg m ^-3 [ g cm^-3]

Calculate the rate of the following situation:

(a) 300g of long beans is sold for RM2.25. Calculate the price for 1kg of long beans.


price of 1kg long bean

 $=\frac{1kg}{0.3\ kg}\times RM2.25$   $=\ RM\ 7.50$