Adam pays $11.10 for 4 stickers and 3 beads.
A sticker costs $2.60 more than 1 bead.
What is the cost of 3 stickers and 4 beads?
Choose the cheaper item to be 1 u.
1 sticker costs $2.60 more than 1 bead.
The cheaper item is the bead.

Cost of the bead = 1 u
Cost of the sticker = 1 u + 2.60

Cost of 4 stickers = 4 x (1 u + 2.60) = 4 u + 10.40
Cost of 3 beads = 3 u

Total cost of 4 stickers and 3 beads
= 4 u + 10.40 + 3 u
= 4 u + 3 u + 10.40
= 7 u + 10.40

7 u + 10.40 = 11.10
7 u = 11.10 - 10.40
7 u = 0.70

1 u = 0.70 ÷ 7 = 0.10

Cost of 3 stickers and 4 beads
= 3 x (1 u + 2.60) + 4 u
= 3 u + 7.80 + 4 u
= 3 u + 4 u + 7.80
= 7 u + 7.80
= 7 x 0.10 + 7.80
= 0.70 + 7.80
= $8.50

Answer(s): $8.50