Adam pays $19.30 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 2 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 = 19.30
9 u = 19.30 - 2.20
9 u = 17.10
1 u = 17.10 ÷ 9 = 1.90
Cost of 1 marble
= 1.90 + 2.20
= $4.10
(b)
Cost of 8 marbles and 2 stickers
= 8 x 4.10 + 2 x 1.90
= 32.80 + 3.80
= $36.60
Answer(s): (a) $4.10; (b) $36.60