Adam pays $36.70 for 1 marble and 8 stickers.
The marble costs $1.60 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 + 1.60
Cost of 8 stickers
= 8 x 1 u
= 8 u
Total cost of 1 marble and 8 stickers
= 1 u + 1.60 + 8 u
= 9 u + 1.60
9 u + 1.60 = 36.70
9 u = 36.70 - 1.60
9 u = 35.10
1 u = 35.10 ÷ 9 = 3.90
Cost of 1 marble
= 3.90 + 1.60
= $5.50
(b)
Cost of 8 marbles and 5 stickers
= 8 x 5.50 + 5 x 3.90
= 44.00 + 19.50
= $63.50
Answer(s): (a) $5.50; (b) $63.50