Adam pays $24.30 for 1 marble and 8 stickers.
The marble costs $2.70 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 8 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 + 2.70
Cost of 8 stickers
= 8 x 1 u
= 8 u
Total cost of 1 marble and 8 stickers
= 1 u + 2.70 + 8 u
= 9 u + 2.70
9 u + 2.70 = 24.30
9 u = 24.30 - 2.70
9 u = 21.60
1 u = 21.60 ÷ 9 = 2.40
Cost of 1 marble
= 2.40 + 2.70
= $5.10
(b)
Cost of 8 marbles and 2 stickers
= 8 x 5.10 + 2 x 2.40
= 40.80 + 4.80
= $45.60
Answer(s): (a) $5.10; (b) $45.60