4 stickers and 1 bead cost $20.90.
1 sticker and 4 beads cost $11.60.
- 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 5 stickers and 5 beads.
(a)
4 stickers + 1 bead = 20.90 --- (1)
1 sticker + 4 beads = 11.60 --- (2)
(1) + (2)
5 stickers + 5 beads = 20.90 + 11.60
5 stickers + 5 beads = 32.50 --- (3)
(3)
÷ 55 stickers + 5 beads = 32.50
1 sticker + 1 bead = 32.50 ÷ 5
1 sticker + 1 bead = 6.50 --- (4)
(b)
(2) - (4)
(1 sticker + 4 beads) - (1 sticker + 1 marble) = 11.60 - 6.50
1 sticker - 1 sticker + 4 beads - 1 bead = 5.10
3 beads = 5.10
1 bead = 5.10 ÷ 3 = 1.70
Cost of 1 bead = $1.70
(c)
Substitute 1 bead = 1.70 into (4).
1 sticker + 1 bead = 6.50
1 sticker + 1.70 = 6.50
1 sticker = 6.50 - 1.70 = 4.80
Cost of 1 sticker = $4.80
(d)
(4)
x 5 1 sticker + 1 bead = 6.50
5 x (1 sticker + 1 marble) = 5 x 6.50
5 stickers + 5 beads = 32.50
Cost of 5 stickers and 5 beads = $32.50
Answer(s): (a) $6.50; (b) $1.70; (c) $4.80; (d) $32.50