Adam pays $27.60 for 1 marble and 6 stickers.
The marble costs $1.70 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 + 1.70
Cost of 6 stickers
= 6 x 1 u
= 6 u
Total cost of 1 marble and 6 stickers
= 1 u + 1.70 + 6 u
= 7 u + 1.70
7 u + 1.70 = 27.60
7 u = 27.60 - 1.70
7 u = 25.90
1 u = 25.90 ÷ 7 = 3.70
Cost of 1 marble
= 3.70 + 1.70
= $5.40
(b)
Cost of 6 marbles and 4 stickers
= 6 x 5.40 + 4 x 3.70
= 32.40 + 14.80
= $47.20
Answer(s): (a) $5.40; (b) $47.20