Adam pays $24.50 for 1 marble and 6 stickers.
The marble costs $2.10 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 6 marbles and 4 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.10
Cost of 6 stickers
= 6 x 1 u
= 6 u
Total cost of 1 marble and 6 stickers
= 1 u + 2.10 + 6 u
= 7 u + 2.10
7 u + 2.10 = 24.50
7 u = 24.50 - 2.10
7 u = 22.40
1 u = 22.40 ÷ 7 = 3.20
Cost of 1 marble
= 3.20 + 2.10
= $5.30
(b)
Cost of 6 marbles and 4 stickers
= 6 x 5.30 + 4 x 3.20
= 31.80 + 12.80
= $44.60
Answer(s): (a) $5.30; (b) $44.60