3 stickers and 1 bead cost $7.20.
1 sticker and 3 beads cost $11.20.
- Find the cost of 1 sticker and 1 bead.
- Find the cost of 1 bead.
- Find the cost of 1 sticker.
- Find the cost of 4 stickers and 4 beads.
(a)
3 stickers + 1 bead = 7.20 --- (1)
1 sticker + 3 beads = 11.20 --- (2)
(1) + (2)
4 stickers + 4 beads = 7.20 + 11.20
4 stickers + 4 beads = 18.40 --- (3)
(3)
÷ 44 stickers + 4 beads = 18.40
1 sticker + 1 bead = 18.40 ÷ 4
1 sticker + 1 bead = 4.60 --- (4)
(b)
(2) - (4)
(1 sticker + 3 beads) - (1 sticker + 1 marble) = 11.20 - 4.60
1 sticker - 1 sticker + 3 beads - 1 bead = 6.60
2 beads = 6.60
1 bead = 6.60 ÷ 2 = 3.30
Cost of 1 bead = $3.30
(c)
Substitute 1 bead = 3.30 into (4).
1 sticker + 1 bead = 4.60
1 sticker + 3.30 = 4.60
1 sticker = 4.60 - 3.30 = 1.30
Cost of 1 sticker = $1.30
(d)
(4)
x 4 1 sticker + 1 bead = 4.60
4 x (1 sticker + 1 marble) = 4 x 4.60
4 stickers + 4 beads = 18.40
Cost of 4 stickers and 4 beads = $18.40
Answer(s): (a) $4.60; (b) $3.30; (c) $1.30; (d) $18.40