Adam pays $21.50 for 1 marble and 5 stickers.
The marble costs $2.30 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 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 + 2.30
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 2.30 + 5 u
= 6 u + 2.30
6 u + 2.30 = 21.50
6 u = 21.50 - 2.30
6 u = 19.20
1 u = 19.20 ÷ 6 = 3.20
Cost of 1 marble
= 3.20 + 2.30
= $5.50
(b)
Cost of 5 marbles and 2 stickers
= 5 x 5.50 + 2 x 3.20
= 27.50 + 6.40
= $33.90
Answer(s): (a) $5.50; (b) $33.90