Mary has 20 biscuits in a tin. There are: 11 plain biscuits. 7 chocolate biscuits. 2 currant biscuits. Sue takes at random two biscuits from the tin. Work out the probability that the two biscuits were not the same type.

This law is sometimes called the grouping property. as you can see, regardless of how the numbers are grouped, the answer is still 13. the associative law of multiplication is similar to the same law for addition. it says that no matter how you group numbers you are multiplying together, you will get the same answer.