Adam spends $12.10 on 2 stickers and 3 marbles.
A sticker costs $1.30 more than 1 marble.
- How much does 1 sticker cost?
- How much do 6 stickers cost?
- How much do a marble and 6 stickers cost?
- How much do 6 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 + 1.30
Total cost of 2 stickers and 3 marbles
= 2(1 u + 1.30) + 3 u
= 2 u + 2.60 + 3 u
= 2 u + 3 u + 2.60
= 5 u + 2.60
5 u + 2.60 = 12.10
5 u = 12.10 - 2.60
5 u = 9.50
1 u = 9.50 ÷ 5 = 1.90
Cost of 1 sticker
= 1 u + 1.30
= 1.90 + 1.30
= $3.20
(b)
Cost of 6 stickers
= 6 x 3.20
= $19.20
(c)
Cost of 1 marble and 6 stickers
= 1.90 + 19.20
= $21.10
(d)
Cost of 6 stickers more than 1 marble
= 19.20 - 1.90
= $17.30
Answer(s): (a) $3.20; (b) $19.20; (c) $21.10; (d) $17.30