Adam pays $35.30 for 1 marble and 4 stickers.
The marble costs $2.80 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 4 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 + 2.80
Cost of 4 stickers
= 4 x 1 u
= 4 u
Total cost of 1 marble and 4 stickers
= 1 u + 2.80 + 4 u
= 5 u + 2.80
5 u + 2.80 = 35.30
5 u = 35.30 - 2.80
5 u = 32.50
1 u = 32.50 ÷ 5 = 6.50
Cost of 1 marble
= 6.50 + 2.80
= $9.30
(b)
Cost of 4 marbles and 7 stickers
= 4 x 9.30 + 7 x 6.50
= 37.20 + 45.50
= $82.70
Answer(s): (a) $9.30; (b) $82.70