Adam pays $18.50 for 1 marble and 6 stickers.
The marble costs $2.40 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 6 marbles and 8 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.40
Cost of 6 stickers
= 6 x 1 u
= 6 u
Total cost of 1 marble and 6 stickers
= 1 u + 2.40 + 6 u
= 7 u + 2.40
7 u + 2.40 = 18.50
7 u = 18.50 - 2.40
7 u = 16.10
1 u = 16.10 ÷ 7 = 2.30
Cost of 1 marble
= 2.30 + 2.40
= $4.70
(b)
Cost of 6 marbles and 8 stickers
= 6 x 4.70 + 8 x 2.30
= 28.20 + 18.40
= $46.60
Answer(s): (a) $4.70; (b) $46.60