Adam pays $44.50 for 1 marble and 7 stickers.
The marble costs $1.30 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 7 marbles and 3 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 1.30
Cost of 7 stickers
= 7 x 1 u
= 7 u
Total cost of 1 marble and 7 stickers
= 1 u + 1.30 + 7 u
= 8 u + 1.30
8 u + 1.30 = 44.50
8 u = 44.50 - 1.30
8 u = 43.20
1 u = 43.20 ÷ 8 = 5.40
Cost of 1 marble
= 5.40 + 1.30
= $6.70
(b)
Cost of 7 marbles and 3 stickers
= 7 x 6.70 + 3 x 5.40
= 46.90 + 16.20
= $63.10
Answer(s): (a) $6.70; (b) $63.10