Adam spends $14.90 on 2 stickers and 3 marbles.
A sticker costs $2.20 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 + 2.20
Total cost of 2 stickers and 3 marbles
= 2(1 u + 2.20) + 3 u
= 2 u + 4.40 + 3 u
= 2 u + 3 u + 4.40
= 5 u + 4.40
5 u + 4.40 = 14.90
5 u = 14.90 - 4.40
5 u = 10.50
1 u = 10.50 ÷ 5 = 2.10
Cost of 1 sticker
= 1 u + 2.20
= 2.10 + 2.20
= $4.30
(b)
Cost of 4 stickers
= 4 x 4.30
= $17.20
(c)
Cost of 1 marble and 4 stickers
= 2.10 + 17.20
= $19.30
(d)
Cost of 4 stickers more than 1 marble
= 17.20 - 2.10
= $15.10
Answer(s): (a) $4.30; (b) $17.20; (c) $19.30; (d) $15.10