Adam pays $42.10 for 1 marble and 6 stickers.
The marble costs $2.90 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 + 2.90
Cost of 6 stickers
= 6 x 1 u
= 6 u
Total cost of 1 marble and 6 stickers
= 1 u + 2.90 + 6 u
= 7 u + 2.90
7 u + 2.90 = 42.10
7 u = 42.10 - 2.90
7 u = 39.20
1 u = 39.20 ÷ 7 = 5.60
Cost of 1 marble
= 5.60 + 2.90
= $8.50
(b)
Cost of 6 marbles and 4 stickers
= 6 x 8.50 + 4 x 5.60
= 51.00 + 22.40
= $73.40
Answer(s): (a) $8.50; (b) $73.40