Adam spends $16.10 on 2 stickers and 3 marbles.
A sticker costs $1.80 more than 1 marble.
- How much does 1 sticker cost?
- How much do 4 stickers cost?
- How much do a marble and 4 stickers cost?
- How much do 4 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 + 1.80
Total cost of 2 stickers and 3 marbles
= 2(1 u + 1.80) + 3 u
= 2 u + 3.60 + 3 u
= 2 u + 3 u + 3.60
= 5 u + 3.60
5 u + 3.60 = 16.10
5 u = 16.10 - 3.60
5 u = 12.50
1 u = 12.50 ÷ 5 = 2.50
Cost of 1 sticker
= 1 u + 1.80
= 2.50 + 1.80
= $4.30
(b)
Cost of 4 stickers
= 4 x 4.30
= $17.20
(c)
Cost of 1 marble and 4 stickers
= 2.50 + 17.20
= $19.70
(d)
Cost of 4 stickers more than 1 marble
= 17.20 - 2.50
= $14.70
Answer(s): (a) $4.30; (b) $17.20; (c) $19.70; (d) $14.70