In a particular region, most farms have livestock and crops. A survey of 21 farms showed that 15 grow crops, 9 have cattle, and 11 have sheep. 4 have sheep and cattle, 7 have cattle and crops, and 8 have sheep and crops. 2 have neither animals nor crops.
(1) Display the information on a Venn diagram.
(2) Hence find the number of farms with:
- only crops
- only animals
- exactly one type of animal, and crops.