Adam pays $19.10 for 1 marble and 8 stickers.
The marble costs $2.90 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 + 2.90
Cost of 8 stickers
= 8 x 1 u
= 8 u
Total cost of 1 marble and 8 stickers
= 1 u + 2.90 + 8 u
= 9 u + 2.90
9 u + 2.90 = 19.10
9 u = 19.10 - 2.90
9 u = 16.20
1 u = 16.20 ÷ 9 = 1.80
Cost of 1 marble
= 1.80 + 2.90
= $4.70
(b)
Cost of 8 marbles and 5 stickers
= 8 x 4.70 + 5 x 1.80
= 37.60 + 9.00
= $46.60
Answer(s): (a) $4.70; (b) $46.60