Adam spends $15.40 on 2 stickers and 3 marbles.
A sticker costs 4 times as much as 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 does 1 marble cost less than 3 stickers?
(a)
Let the cheaper item be 1 u.
Cost of 1 marble = 1 u
Cost of 1 sticker = 4 u
Cost of 2 stickers = 2 x 4 u = 8 u
Cost of 3 marbles = 3 x 1 u = 3 u
Total cost of 2 stickers and 3 marbles
= 8 u + 3 u
= 11 u
11 u = 15.40
1 u = 15.40 ÷ 11 = 1.40
Cost of 1 sticker
= 4 u
= 4 x 1.40
= $5.60
(b)
Cost of 3 stickers
= 3 x 5.60
= $16.80
(c)
Cost of 1 marble and 3 stickers
= 1.40 + 16.80
= $18.20
(d)
Cost of 1 marble less than 3 stickers
= 16.80 - 1.40
= $15.40
Answer(s): (a) $5.60; (b) $16.80; (c) $18.20; (d) $15.40