Adam pays $27.20 for 1 marble and 4 stickers.
The marble costs $2.70 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 4 marbles and 8 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 4 stickers
= 4 x 1 u
= 4 u
Total cost of 1 marble and 4 stickers
= 1 u + 2.70 + 4 u
= 5 u + 2.70
5 u + 2.70 = 27.20
5 u = 27.20 - 2.70
5 u = 24.50
1 u = 24.50 ÷ 5 = 4.90
Cost of 1 marble
= 4.90 + 2.70
= $7.60
(b)
Cost of 4 marbles and 8 stickers
= 4 x 7.60 + 8 x 4.90
= 30.40 + 39.20
= $69.60
Answer(s): (a) $7.60; (b) $69.60