Rates and Ratio

1. What is the difference between a rate and a ratio?

rate is a comparison of kinds of quantities measured in different units.

e.g. km / hr (kilometres per hour)
or L/s (litres / second)

The speed limit in towns is 50 km / h

ratio compares the kinds of quantities measured in the same units.

e.g. In baking: 300g of flour to every 100g of butter

This ratio would be written 300 : 100 or 3 : 1

2. Should ratios always be written in their simplest form?

Usually ratios should be written in their simplest form although sometimes it may be clearer to understand and solve a problem if they are kept in some other form.

Ratios can also be written as fractions or percentages.