Adam pays $15.40 for 1 marble and 4 stickers.
The marble costs $2.90 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 4 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 + 2.90
Cost of 4 stickers
= 4 x 1 u
= 4 u
Total cost of 1 marble and 4 stickers
= 1 u + 2.90 + 4 u
= 5 u + 2.90
5 u + 2.90 = 15.40
5 u = 15.40 - 2.90
5 u = 12.50
1 u = 12.50 ÷ 5 = 2.50
Cost of 1 marble
= 2.50 + 2.90
= $5.40
(b)
Cost of 4 marbles and 8 stickers
= 4 x 5.40 + 8 x 2.50
= 21.60 + 20.00
= $41.60
Answer(s): (a) $5.40; (b) $41.60