If Adam buys 3 stickers and 4 beads, it costs $40.50.
If Adam buys 4 stickers and 3 beads, he will have $6.80 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 = 40.50 --- (1)
4 stickers + 3 beads = 40.50 - 6.80 = 33.70 --- (2)
(1) + (2)
7 stickers + 7 beads = 74.20 --- (3)
(3)
÷ 7 1 sticker + 1 bead = 74.20 ÷ 7 = 10.60 --- (4)
Cost of 1 sticker and 1 bead = $10.60
(b)
(4)
x 3 3 stickers + 3 beads = 3 x 10.60 = 31.80 --- (5)
(2) - (5)
4 stickers + 3 beads - 3 stickers - 3 beads = 33.70 - 31.80
4 stickers - 3 stickers - 3 beads + 3 beads = 1.90
1 sticker = 1.90
Cost of 1 sticker = $1.90
(c)
Substitute 1 sticker = 1.90 into (4).
1 sticker + 1 bead = 10.60
1.90 + 1 bead = 10.60
1 bead = 10.60 - 1.90 = 8.70
Cost of 1 bead = $8.70
Answer(s): (a) $10.60; (b) $1.90; (c) $8.70