Adam pays $27.10 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 7 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 = 27.10
7 u = 27.10 - 2.60
7 u = 24.50
1 u = 24.50 ÷ 7 = 3.50
Cost of 1 marble
= 3.50 + 2.60
= $6.10
(b)
Cost of 6 marbles and 7 stickers
= 6 x 6.10 + 7 x 3.50
= 36.60 + 24.50
= $61.10
Answer(s): (a) $6.10; (b) $61.10