Adam pays $43.40 for 1 marble and 8 stickers.
The marble costs $1.10 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 8 marbles and 4 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 1.10
Cost of 8 stickers
= 8 x 1 u
= 8 u
Total cost of 1 marble and 8 stickers
= 1 u + 1.10 + 8 u
= 9 u + 1.10
9 u + 1.10 = 43.40
9 u = 43.40 - 1.10
9 u = 42.30
1 u = 42.30 ÷ 9 = 4.70
Cost of 1 marble
= 4.70 + 1.10
= $5.80
(b)
Cost of 8 marbles and 4 stickers
= 8 x 5.80 + 4 x 4.70
= 46.40 + 18.80
= $65.20
Answer(s): (a) $5.80; (b) $65.20