Adam spends $16.90 on 2 stickers and 3 marbles.
A sticker costs $2.20 more than 1 marble.
- How much does 1 sticker cost?
- How much do 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 + 2.20
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 = 16.90
5 u = 16.90 - 4.40
5 u = 12.50
1 u = 12.50 ÷ 5 = 2.50
Cost of 1 sticker
= 1 u + 2.20
= 2.50 + 2.20
= $4.70
(b)
Cost of 8 stickers
= 8 x 4.70
= $37.60
(c)
Cost of 1 marble and 8 stickers
= 2.50 + 37.60
= $40.10
(d)
Cost of 8 stickers more than 1 marble
= 37.60 - 2.50
= $35.10
Answer(s): (a) $4.70; (b) $37.60; (c) $40.10; (d) $35.10