Adam pays $34.10 for 1 marble and 8 stickers.
The marble costs $1.70 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 + 1.70
Cost of 8 stickers
= 8 x 1 u
= 8 u
Total cost of 1 marble and 8 stickers
= 1 u + 1.70 + 8 u
= 9 u + 1.70
9 u + 1.70 = 34.10
9 u = 34.10 - 1.70
9 u = 32.40
1 u = 32.40 ÷ 9 = 3.60
Cost of 1 marble
= 3.60 + 1.70
= $5.30
(b)
Cost of 8 marbles and 4 stickers
= 8 x 5.30 + 4 x 3.60
= 42.40 + 14.40
= $56.80
Answer(s): (a) $5.30; (b) $56.80