Adam spends $12.10 on 2 stickers and 3 marbles.
A sticker costs $2.80 more than 1 marble.
- How much does 1 sticker cost?
- How much do 8 stickers cost?
- How much do a marble and 8 stickers cost?
- How much do 8 stickers cost more than 1 marble?
(a)
Let the cheaper item be 1 u.
Cost of 1 marble = 1 u
Cost of 1 sticker = 1 u + 2.80
Total cost of 2 stickers and 3 marbles
= 2(1 u + 2.80) + 3 u
= 2 u + 5.60 + 3 u
= 2 u + 3 u + 5.60
= 5 u + 5.60
5 u + 5.60 = 12.10
5 u = 12.10 - 5.60
5 u = 6.50
1 u = 6.50 ÷ 5 = 1.30
Cost of 1 sticker
= 1 u + 2.80
= 1.30 + 2.80
= $4.10
(b)
Cost of 8 stickers
= 8 x 4.10
= $32.80
(c)
Cost of 1 marble and 8 stickers
= 1.30 + 32.80
= $34.10
(d)
Cost of 8 stickers more than 1 marble
= 32.80 - 1.30
= $31.50
Answer(s): (a) $4.10; (b) $32.80; (c) $34.10; (d) $31.50