Adam pays $44.30 for 1 marble and 7 stickers.
The marble costs $2.70 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 7 marbles and 6 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.70
Cost of 7 stickers
= 7 x 1 u
= 7 u
Total cost of 1 marble and 7 stickers
= 1 u + 2.70 + 7 u
= 8 u + 2.70
8 u + 2.70 = 44.30
8 u = 44.30 - 2.70
8 u = 41.60
1 u = 41.60 ÷ 8 = 5.20
Cost of 1 marble
= 5.20 + 2.70
= $7.90
(b)
Cost of 7 marbles and 6 stickers
= 7 x 7.90 + 6 x 5.20
= 55.30 + 31.20
= $86.50
Answer(s): (a) $7.90; (b) $86.50