Adam pays $11.90 for 2 beads and 3 stickers.
A bead costs $2.20 more than 1 sticker.
What is the cost of 4 beads and 3 stickers?
Choose the cheaper item to be 1 u.
1 bead costs $2.20 more than 1 sticker.
The cheaper item is the sticker.

Cost of the sticker = 1 u
Cost of the bead = 1 u + 2.20

Cost of 2 beads = 2 x (1 u + 2.20) = 2 u + 4.40
Cost of 3 stickers = 3 u

Total cost of 2 beads and 3 stickers
= 2 u + 4.40 + 3 u
= 2 u + 3 u + 4.40
= 5 u + 4.40

5 u + 4.40 = 11.90
5 u = 11.90 - 4.40
5 u = 7.50

1 u = 7.50 ÷ 5 = 1.50

Cost of 4 beads and 3 stickers
= 4 x (1 u + 2.20) + 3 u
= 4 u + 8.80 + 3 u
= 4 u + 3 u + 8.80
= 7 u + 8.80
= 7 x 1.50 + 8.80
= 10.50 + 8.80
= $19.30

Answer(s): $19.30