Adam pays $17.70 for 1 marble and 5 stickers.
The marble costs $2.10 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 marbles and 4 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.10
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 2.10 + 5 u
= 6 u + 2.10
6 u + 2.10 = 17.70
6 u = 17.70 - 2.10
6 u = 15.60
1 u = 15.60 ÷ 6 = 2.60
Cost of 1 marble
= 2.60 + 2.10
= $4.70
(b)
Cost of 5 marbles and 4 stickers
= 5 x 4.70 + 4 x 2.60
= 23.50 + 10.40
= $33.90
Answer(s): (a) $4.70; (b) $33.90