Adam pays $16.80 for 1 marble and 4 stickers.
The marble costs $1.30 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 + 1.30
Cost of 4 stickers
= 4 x 1 u
= 4 u
Total cost of 1 marble and 4 stickers
= 1 u + 1.30 + 4 u
= 5 u + 1.30
5 u + 1.30 = 16.80
5 u = 16.80 - 1.30
5 u = 15.50
1 u = 15.50 ÷ 5 = 3.10
Cost of 1 marble
= 3.10 + 1.30
= $4.40
(b)
Cost of 4 marbles and 6 stickers
= 4 x 4.40 + 6 x 3.10
= 17.60 + 18.60
= $36.20
Answer(s): (a) $4.40; (b) $36.20