Adam pays $20.70 for 1 marble and 4 stickers.
The marble costs $2.20 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 4 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 + 2.20
Cost of 4 stickers
= 4 x 1 u
= 4 u
Total cost of 1 marble and 4 stickers
= 1 u + 2.20 + 4 u
= 5 u + 2.20
5 u + 2.20 = 20.70
5 u = 20.70 - 2.20
5 u = 18.50
1 u = 18.50 ÷ 5 = 3.70
Cost of 1 marble
= 3.70 + 2.20
= $5.90
(b)
Cost of 4 marbles and 3 stickers
= 4 x 5.90 + 3 x 3.70
= 23.60 + 11.10
= $34.70
Answer(s): (a) $5.90; (b) $34.70