Adam spends $12.60 on 2 marbles and 3 stickers.
A marble costs 2 times as much as 1 sticker.
- How much does 1 marble cost?
- How much do 4 marbles cost?
- How much do a sticker and 4 marbles cost?
- How much does 1 sticker cost less than 4 marbles?
(a)
Let the cheaper item be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 2 u
Cost of 2 marbles = 2 x 2 u = 4 u
Cost of 3 stickers = 3 x 1 u = 3 u
Total cost of 2 marbles and 3 stickers
= 4 u + 3 u
= 7 u
7 u = 12.60
1 u = 12.60 ÷ 7 = 1.80
Cost of 1 marble
= 2 u
= 2 x 1.80
= $3.60
(b)
Cost of 4 marbles
= 4 x 3.60
= $14.40
(c)
Cost of 1 sticker and 4 marbles
= 1.80 + 14.40
= $16.20
(d)
Cost of 1 sticker less than 4 marbles
= 14.40 - 1.80
= $12.60
Answer(s): (a) $3.60; (b) $14.40; (c) $16.20; (d) $12.60