Adam spends $15.60 on 3 stickers and 4 marbles.
A sticker costs 3 times as much as 1 marble.
- How much does 1 sticker cost?
- How much do 4 stickers cost?
- How much do a marble and 4 stickers cost?
- How much does 1 marble cost less than 4 stickers?
(a)
Let the cheaper item be 1 u.
Cost of 1 marble = 1 u
Cost of 1 sticker = 3 u
Cost of 3 stickers = 3 x 3 u = 9 u
Cost of 4 marbles = 4 x 1 u = 4 u
Total cost of 3 stickers and 4 marbles
= 9 u + 4 u
= 13 u
13 u = 15.60
1 u = 15.60 ÷ 13 = 1.20
Cost of 1 sticker
= 3 u
= 3 x 1.20
= $3.60
(b)
Cost of 4 stickers
= 4 x 3.60
= $14.40
(c)
Cost of 1 marble and 4 stickers
= 1.20 + 14.40
= $15.60
(d)
Cost of 1 marble less than 4 stickers
= 14.40 - 1.20
= $13.20
Answer(s): (a) $3.60; (b) $14.40; (c) $15.60; (d) $13.20
