20% of 120 is 24.
To find this answer, you need to use the percentage formula (is over of equals the percentage over 100, is/of = p/100).
Plug in the known numbers. You know you need 20%, so plug 20 into the percentage place.
is/of = 20/100
You know the "of," which is 120, so plug that in.
is/120 = 20/100
You don't know the "is," so to find it you need to multiply cross multiply 120 by 20. Then you need to divide your answer by 100 to find your missing value (is).
120 * 20 = 2,400
2,400 / 100 = 24