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