Adam spends $15.30 on 4 stickers and 5 marbles.
A sticker costs 3 times as much as 1 marble.
- How much does 1 sticker cost?
- How much do 5 stickers cost?
- How much do a marble and 5 stickers cost?
- How much does 1 marble cost less than 5 stickers?
(a)
Let the cheaper item be 1 u.
Cost of 1 marble = 1 u
Cost of 1 sticker = 3 u
Cost of 4 stickers = 4 x 3 u = 12 u
Cost of 5 marbles = 5 x 1 u = 5 u
Total cost of 4 stickers and 5 marbles
= 12 u + 5 u
= 17 u
17 u = 15.30
1 u = 15.30 ÷ 17 = 0.90
Cost of 1 sticker
= 3 u
= 3 x 0.90
= $2.70
(b)
Cost of 5 stickers
= 5 x 2.70
= $13.50
(c)
Cost of 1 marble and 5 stickers
= 0.90 + 13.50
= $14.40
(d)
Cost of 1 marble less than 5 stickers
= 13.50 - 0.90
= $12.60
Answer(s): (a) $2.70; (b) $13.50; (c) $14.40; (d) $12.60