Adam pays $24.30 for 1 marble and 6 stickers.
The marble costs $2.60 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 6 marbles and 4 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.60
Cost of 6 stickers
= 6 x 1 u
= 6 u
Total cost of 1 marble and 6 stickers
= 1 u + 2.60 + 6 u
= 7 u + 2.60
7 u + 2.60 = 24.30
7 u = 24.30 - 2.60
7 u = 21.70
1 u = 21.70 ÷ 7 = 3.10
Cost of 1 marble
= 3.10 + 2.60
= $5.70
(b)
Cost of 6 marbles and 4 stickers
= 6 x 5.70 + 4 x 3.10
= 34.20 + 12.40
= $46.60
Answer(s): (a) $5.70; (b) $46.60