Adam pays $36.60 for 1 marble and 8 stickers.
The marble costs $1.50 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 8 marbles and 5 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 1.50
Cost of 8 stickers
= 8 x 1 u
= 8 u
Total cost of 1 marble and 8 stickers
= 1 u + 1.50 + 8 u
= 9 u + 1.50
9 u + 1.50 = 36.60
9 u = 36.60 - 1.50
9 u = 35.10
1 u = 35.10 ÷ 9 = 3.90
Cost of 1 marble
= 3.90 + 1.50
= $5.40
(b)
Cost of 8 marbles and 5 stickers
= 8 x 5.40 + 5 x 3.90
= 43.20 + 19.50
= $62.70
Answer(s): (a) $5.40; (b) $62.70