Adam pays $22.30 for 1 marble and 6 stickers.
The marble costs $2.70 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 + 2.70
Cost of 6 stickers
= 6 x 1 u
= 6 u
Total cost of 1 marble and 6 stickers
= 1 u + 2.70 + 6 u
= 7 u + 2.70
7 u + 2.70 = 22.30
7 u = 22.30 - 2.70
7 u = 19.60
1 u = 19.60 ÷ 7 = 2.80
Cost of 1 marble
= 2.80 + 2.70
= $5.50
(b)
Cost of 6 marbles and 4 stickers
= 6 x 5.50 + 4 x 2.80
= 33.00 + 11.20
= $44.20
Answer(s): (a) $5.50; (b) $44.20