Adam pays $34.90 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 3 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 = 34.90
7 u = 34.90 - 2.70
7 u = 32.20
1 u = 32.20 ÷ 7 = 4.60
Cost of 1 marble
= 4.60 + 2.70
= $7.30
(b)
Cost of 6 marbles and 3 stickers
= 6 x 7.30 + 3 x 4.60
= 43.80 + 13.80
= $57.60
Answer(s): (a) $7.30; (b) $57.60