Adam pays $24.20 for 1 marble and 5 stickers.
The marble costs $2.60 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 marbles and 7 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.60
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 2.60 + 5 u
= 6 u + 2.60
6 u + 2.60 = 24.20
6 u = 24.20 - 2.60
6 u = 21.60
1 u = 21.60 ÷ 6 = 3.60
Cost of 1 marble
= 3.60 + 2.60
= $6.20
(b)
Cost of 5 marbles and 7 stickers
= 5 x 6.20 + 7 x 3.60
= 31.00 + 25.20
= $56.20
Answer(s): (a) $6.20; (b) $56.20