Adam pays $21.90 for 1 marble and 4 stickers.
The marble costs $2.40 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 4 marbles and 6 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 4 stickers
= 4 x 1 u
= 4 u
Total cost of 1 marble and 4 stickers
= 1 u + 2.40 + 4 u
= 5 u + 2.40
5 u + 2.40 = 21.90
5 u = 21.90 - 2.40
5 u = 19.50
1 u = 19.50 ÷ 5 = 3.90
Cost of 1 marble
= 3.90 + 2.40
= $6.30
(b)
Cost of 4 marbles and 6 stickers
= 4 x 6.30 + 6 x 3.90
= 25.20 + 23.40
= $48.60
Answer(s): (a) $6.30; (b) $48.60