Adam pays $44.60 for 1 marble and 7 stickers.
The marble costs $2.20 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 7 marbles and 3 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.20
Cost of 7 stickers
= 7 x 1 u
= 7 u
Total cost of 1 marble and 7 stickers
= 1 u + 2.20 + 7 u
= 8 u + 2.20
8 u + 2.20 = 44.60
8 u = 44.60 - 2.20
8 u = 42.40
1 u = 42.40 ÷ 8 = 5.30
Cost of 1 marble
= 5.30 + 2.20
= $7.50
(b)
Cost of 7 marbles and 3 stickers
= 7 x 7.50 + 3 x 5.30
= 52.50 + 15.90
= $68.40
Answer(s): (a) $7.50; (b) $68.40