Adam pays $36.10 for 1 marble and 8 stickers.
The marble costs $1.90 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 8 marbles and 6 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 1.90
Cost of 8 stickers
= 8 x 1 u
= 8 u
Total cost of 1 marble and 8 stickers
= 1 u + 1.90 + 8 u
= 9 u + 1.90
9 u + 1.90 = 36.10
9 u = 36.10 - 1.90
9 u = 34.20
1 u = 34.20 ÷ 9 = 3.80
Cost of 1 marble
= 3.80 + 1.90
= $5.70
(b)
Cost of 8 marbles and 6 stickers
= 8 x 5.70 + 6 x 3.80
= 45.60 + 22.80
= $68.40
Answer(s): (a) $5.70; (b) $68.40