Adam spends $14.10 on 2 stickers and 3 marbles.
A sticker costs $2.80 more than 1 marble.
- How much does 1 sticker cost?
- How much do 3 stickers cost?
- How much do a marble and 3 stickers cost?
- How much do 3 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 + 2.80
Total cost of 2 stickers and 3 marbles
= 2(1 u + 2.80) + 3 u
= 2 u + 5.60 + 3 u
= 2 u + 3 u + 5.60
= 5 u + 5.60
5 u + 5.60 = 14.10
5 u = 14.10 - 5.60
5 u = 8.50
1 u = 8.50 ÷ 5 = 1.70
Cost of 1 sticker
= 1 u + 2.80
= 1.70 + 2.80
= $4.50
(b)
Cost of 3 stickers
= 3 x 4.50
= $13.50
(c)
Cost of 1 marble and 3 stickers
= 1.70 + 13.50
= $15.20
(d)
Cost of 3 stickers more than 1 marble
= 13.50 - 1.70
= $11.80
Answer(s): (a) $4.50; (b) $13.50; (c) $15.20; (d) $11.80
