Adam pays $19.60 for 1 marble and 8 stickers.
The marble costs $2.50 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 + 2.50
Cost of 8 stickers
= 8 x 1 u
= 8 u
Total cost of 1 marble and 8 stickers
= 1 u + 2.50 + 8 u
= 9 u + 2.50
9 u + 2.50 = 19.60
9 u = 19.60 - 2.50
9 u = 17.10
1 u = 17.10 ÷ 9 = 1.90
Cost of 1 marble
= 1.90 + 2.50
= $4.40
(b)
Cost of 8 marbles and 5 stickers
= 8 x 4.40 + 5 x 1.90
= 35.20 + 9.50
= $44.70
Answer(s): (a) $4.40; (b) $44.70