• Proportion is a comparison between two different quantities of units and is usually expressed as one quantity per unit of another quantity.
• Rates can be found by dividing the two quantities involved.
• The unit of rate measurement is the unit of numerator per unit of the denominator.

EXAMPLE:

A car can travel 350 km with 50 litres of petrol. How far would it be if the car was only filled with 20 litres of petrol?

SOLUTION:

50 litres = 350 km
20 litres = ___ km

 \(\frac{350 \text{ km}}{50\text{ liter}}=\frac{?}{20\text{ liter}}\)

\(\frac{350}{50}\times{20}=140\)

20 litres = 140 km