30% of what number is 90

What portion of 90 is 30?
a) 20
b) 27
c) 30
d) 33
Answer: a) 20

If you have 30% of a pizza with 8 slices, how many slices do you have?
a) 2.4 slices
b) 2 slices
c) 3 slices
d) 4 slices
Answer: b) 2 slices