Adam pays $24.20 for 1 marble and 6 stickers.
The marble costs $2.50 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 6 marbles and 2 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.50
Cost of 6 stickers
= 6 x 1 u
= 6 u
Total cost of 1 marble and 6 stickers
= 1 u + 2.50 + 6 u
= 7 u + 2.50
7 u + 2.50 = 24.20
7 u = 24.20 - 2.50
7 u = 21.70
1 u = 21.70 ÷ 7 = 3.10
Cost of 1 marble
= 3.10 + 2.50
= $5.60
(b)
Cost of 6 marbles and 2 stickers
= 6 x 5.60 + 2 x 3.10
= 33.60 + 6.20
= $39.80
Answer(s): (a) $5.60; (b) $39.80