Counting combinations
You learn to work out the number of possible combinations from two groups by multiplying.
How to work it out
Are you choosing one from each of two groups? Then multiply the numbers of choices together.
3 soups and 4 rolls
- Look at how many choices the first group has: 3 kinds of soup.
- Look at the second group: 4 kinds of roll.
- Multiply the numbers: 3 × 4 = 12.
- There are 12 possible combinations.
More examples
2 shirts and 5 pairs of trousers
- Multiply the choices: 2 × 5 = 10.
- There are 10 possible combinations.
4 ice-cream flavours and 3 toppings
- Multiply the choices: 4 × 3 = 12.
- There are 12 possible combinations.