Adam spends $14.40 on 2 marbles and 3 stickers.
A marble costs 3 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 = 3 u
Cost of 2 marbles = 2 x 3 u = 6 u
Cost of 3 stickers = 3 x 1 u = 3 u
Total cost of 2 marbles and 3 stickers
= 6 u + 3 u
= 9 u
9 u = 14.40
1 u = 14.40 ÷ 9 = 1.60
Cost of 1 marble
= 3 u
= 3 x 1.60
= $4.80
(b)
Cost of 4 marbles
= 4 x 4.80
= $19.20
(c)
Cost of 1 sticker and 4 marbles
= 1.60 + 19.20
= $20.80
(d)
Cost of 1 sticker less than 4 marbles
= 19.20 - 1.60
= $17.60
Answer(s): (a) $4.80; (b) $19.20; (c) $20.80; (d) $17.60