Adam pays $25.90 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 = 25.90
9 u = 25.90 - 1.60
9 u = 24.30
1 u = 24.30 ÷ 9 = 2.70
Cost of 1 marble
= 2.70 + 1.60
= $4.30
(b)
Cost of 8 marbles and 5 stickers
= 8 x 4.30 + 5 x 2.70
= 34.40 + 13.50
= $47.90
Answer(s): (a) $4.30; (b) $47.90