When Emma has entered some of her data, the table looks like this:
 Has a dog  Does not have a dog 
Has a cat 
8 
4 
Does not have a cat 
12 

Emma has missed out one of the numbers, but we know that there are 30 pupils in her class.

Practice Questions
Work out the answer to each of these questions then click on the button marked
to see whether you are correct.
(a) How many pupils do not have a cat or a dog?
(b) How many pupils have a dog?
(c) How many pupils have a cat?
(d) How many children have at least one of these pets?
