Adam spends $16.70 on 2 stickers and 3 marbles.
A sticker costs $2.10 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 + 2.10
Total cost of 2 stickers and 3 marbles
= 2(1 u + 2.10) + 3 u
= 2 u + 4.20 + 3 u
= 2 u + 3 u + 4.20
= 5 u + 4.20
5 u + 4.20 = 16.70
5 u = 16.70 - 4.20
5 u = 12.50
1 u = 12.50 ÷ 5 = 2.50
Cost of 1 sticker
= 1 u + 2.10
= 2.50 + 2.10
= $4.60
(b)
Cost of 6 stickers
= 6 x 4.60
= $27.60
(c)
Cost of 1 marble and 6 stickers
= 2.50 + 27.60
= $30.10
(d)
Cost of 6 stickers more than 1 marble
= 27.60 - 2.50
= $25.10
Answer(s): (a) $4.60; (b) $27.60; (c) $30.10; (d) $25.10