Adam pays $34.60 for 1 marble and 8 stickers.
The marble costs $2.20 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 8 marbles and 3 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.20
Cost of 8 stickers
= 8 x 1 u
= 8 u
Total cost of 1 marble and 8 stickers
= 1 u + 2.20 + 8 u
= 9 u + 2.20
9 u + 2.20 = 34.60
9 u = 34.60 - 2.20
9 u = 32.40
1 u = 32.40 ÷ 9 = 3.60
Cost of 1 marble
= 3.60 + 2.20
= $5.80
(b)
Cost of 8 marbles and 3 stickers
= 8 x 5.80 + 3 x 3.60
= 46.40 + 10.80
= $57.20
Answer(s): (a) $5.80; (b) $57.20