Answer:
a) photo
b)

each person will get 1/5 of the amount of pizza in the table.
the pizza in the table is 3/4 of the whole pizza.
then each person will get 1/5 of 3/4 of the whole pizza.
c)
if 3/4 of the pizza equals 12 slices, then 4/4 of the pizza (the whole pizza) will have 12 . 1 : 3/4 =16 slices

(Photo)