If Adam buys 3 stickers and 4 beads, it costs $42.40.
If Adam buys 4 stickers and 3 beads, he will have $5.70 left.
- Find the cost of 1 sticker and 1 bead.
- Find the cost of 1 sticker.
- Find the cost of 1 bead.
(a)
3 stickers + 4 beads = 42.40 --- (1)
4 stickers + 3 beads = 42.40 - 5.70 = 36.70 --- (2)
(1) + (2)
7 stickers + 7 beads = 79.10 --- (3)
(3)
÷ 7 1 sticker + 1 bead = 79.10 ÷ 7 = 11.30 --- (4)
Cost of 1 sticker and 1 bead = $11.30
(b)
(4)
x 3 3 stickers + 3 beads = 3 x 11.30 = 33.90 --- (5)
(2) - (5)
4 stickers + 3 beads - 3 stickers - 3 beads = 36.70 - 33.90
4 stickers - 3 stickers - 3 beads + 3 beads = 2.80
1 sticker = 2.80
Cost of 1 sticker = $2.80
(c)
Substitute 1 sticker = 2.80 into (4).
1 sticker + 1 bead = 11.30
2.80 + 1 bead = 11.30
1 bead = 11.30 - 2.80 = 8.50
Cost of 1 bead = $8.50
Answer(s): (a) $11.30; (b) $2.80; (c) $8.50