Adam pays $18.80 for 2 beads and 4 stickers.
A bead costs $1.30 more than 1 sticker.
What is the cost of 3 beads and 4 stickers?
Choose the cheaper item to be 1 u.
1 bead costs $1.30 more than 1 sticker.
The cheaper item is the sticker.

Cost of the sticker = 1 u
Cost of the bead = 1 u + 1.30

Cost of 2 beads = 2 x (1 u + 1.30) = 2 u + 2.60
Cost of 4 stickers = 4 u

Total cost of 2 beads and 4 stickers
= 2 u + 2.60 + 4 u
= 2 u + 4 u + 2.60
= 6 u + 2.60

6 u + 2.60 = 18.80
6 u = 18.80 - 2.60
6 u = 16.20

1 u = 16.20 ÷ 6 = 2.70

Cost of 3 beads and 4 stickers
= 3 x (1 u + 1.30) + 4 u
= 3 u + 3.90 + 4 u
= 3 u + 4 u + 3.90
= 7 u + 3.90
= 7 x 2.70 + 3.90
= 18.90 + 3.90
= $22.80

Answer(s): $22.80