5. In a region of mixed farming, farms keep goats, cattle or sheep. There are 77 farms altogether. 19 farms keep only
goats, 8 keep only cattle and 13 keep only sheep. 13 keep
both goats and cattle, 28 keep both cattle and sheep and
8 keep both goats and sheep.
a) Draw a Venn diagram to show the above information.
b) Calculate n(Gncns).