Adam pays $42.20 for 1 marble and 4 stickers.
The marble costs $1.70 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 + 1.70
Cost of 4 stickers
= 4 x 1 u
= 4 u
Total cost of 1 marble and 4 stickers
= 1 u + 1.70 + 4 u
= 5 u + 1.70
5 u + 1.70 = 42.20
5 u = 42.20 - 1.70
5 u = 40.50
1 u = 40.50 ÷ 5 = 8.10
Cost of 1 marble
= 8.10 + 1.70
= $9.80
(b)
Cost of 4 marbles and 3 stickers
= 4 x 9.80 + 3 x 8.10
= 39.20 + 24.30
= $63.50
Answer(s): (a) $9.80; (b) $63.50