Adam pays $43.50 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 3 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 = 43.50
7 u = 43.50 - 2.90
7 u = 40.60
1 u = 40.60 ÷ 7 = 5.80
Cost of 1 marble
= 5.80 + 2.90
= $8.70
(b)
Cost of 6 marbles and 3 stickers
= 6 x 8.70 + 3 x 5.80
= 52.20 + 17.40
= $69.60
Answer(s): (a) $8.70; (b) $69.60