Since there are 20 total pieces of gum, we divide 20 by 5 to figure out how many groups of 8 pieces of candy there are (For every 8, 5 are gum). This gives us 4 groups of 8. Because for every 8 pieces, 5 are gum, we subtract 5 from 8 and get three. Multiply 3 by 4 (the number of groups), and we get 12 other pieces of candy. Add to 20, and we get 32. To check, divide 32 by the number of groups (4) and we get 8, which is how many pieces of candy are in each group.
