Answer:
26
Step-by-step explanation:
There are 60 pupils in the survey
32 are boys, so we assume 28 are girls
12 of the boys said cola was their favourite
4 boys liked water best.
That is a total of 16 boys who prefer either cola or water out of 32 total boys
There are 16 boys leftover who must have milk as there favourite
9 girls liked water best
21 pupils altogether said milk was there favourite. We know there are 16 boys who said milk was there favourite, meaning 5 of these pupils must be girls.
That means 9 girls have water as their favourite and 5 have milk as their favourite, a total of 14
We know there are 28 girls total. That means 14 of them must have listed cola as their favourite drink.
There are 14 girls and 12 boys who said cola was their favourite, a total of 26 pupils
