Adam pays $34.40 for 1 marble and 8 stickers.
The marble costs $1.10 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 8 marbles and 7 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 1.10
Cost of 8 stickers
= 8 x 1 u
= 8 u
Total cost of 1 marble and 8 stickers
= 1 u + 1.10 + 8 u
= 9 u + 1.10
9 u + 1.10 = 34.40
9 u = 34.40 - 1.10
9 u = 33.30
1 u = 33.30 ÷ 9 = 3.70
Cost of 1 marble
= 3.70 + 1.10
= $4.80
(b)
Cost of 8 marbles and 7 stickers
= 8 x 4.80 + 7 x 3.70
= 38.40 + 25.90
= $64.30
Answer(s): (a) $4.80; (b) $64.30