If Adam buys 3 beads and 4 stickers, it costs $39.90.
If Adam buys 4 beads and 3 stickers, he will have $4.20 left.
- Find the cost of 1 bead and 1 sticker.
- Find the cost of 1 bead.
- Find the cost of 1 sticker.
(a)
3 beads + 4 stickers = 39.90 --- (1)
4 beads + 3 stickers = 39.90 - 4.20 = 35.70 --- (2)
(1) + (2)
7 beads + 7 stickers = 75.60 --- (3)
(3)
÷ 7 1 bead + 1 sticker = 75.60 ÷ 7 = 10.80 --- (4)
Cost of 1 bead and 1 sticker = $10.80
(b)
(4)
x 3 3 beads + 3 stickers = 3 x 10.80 = 32.40 --- (5)
(2) - (5)
4 beads + 3 stickers - 3 beads - 3 stickers = 35.70 - 32.40
4 beads - 3 beads - 3 stickers + 3 stickers = 3.30
1 bead = 3.30
Cost of 1 bead = $3.30
(c)
Substitute 1 bead = 3.30 into (4).
1 bead + 1 sticker = 10.80
3.30 + 1 sticker = 10.80
1 sticker = 10.80 - 3.30 = 7.50
Cost of 1 sticker = $7.50
Answer(s): (a) $10.80; (b) $3.30; (c) $7.50