4 stickers and 1 bead cost $18.60.
1 sticker and 4 beads cost $18.90.
- 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 = 18.60 --- (1)
1 sticker + 4 beads = 18.90 --- (2)
(1) + (2)
5 stickers + 5 beads = 18.60 + 18.90
5 stickers + 5 beads = 37.50 --- (3)
(3)
÷ 55 stickers + 5 beads = 37.50
1 sticker + 1 bead = 37.50 ÷ 5
1 sticker + 1 bead = 7.50 --- (4)
(b)
(2) - (4)
(1 sticker + 4 beads) - (1 sticker + 1 marble) = 18.90 - 7.50
1 sticker - 1 sticker + 4 beads - 1 bead = 11.40
3 beads = 11.40
1 bead = 11.40 ÷ 3 = 3.80
Cost of 1 bead = $3.80
(c)
Substitute 1 bead = 3.80 into (4).
1 sticker + 1 bead = 7.50
1 sticker + 3.80 = 7.50
1 sticker = 7.50 - 3.80 = 3.70
Cost of 1 sticker = $3.70
(d)
(4)
x 5 1 sticker + 1 bead = 7.50
5 x (1 sticker + 1 marble) = 5 x 7.50
5 stickers + 5 beads = 37.50
Cost of 5 stickers and 5 beads = $37.50
Answer(s): (a) $7.50; (b) $3.80; (c) $3.70; (d) $37.50