Adam pays $15.90 for 1 marble and 5 stickers.
The marble costs $2.70 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 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 + 2.70
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 2.70 + 5 u
= 6 u + 2.70
6 u + 2.70 = 15.90
6 u = 15.90 - 2.70
6 u = 13.20
1 u = 13.20 ÷ 6 = 2.20
Cost of 1 marble
= 2.20 + 2.70
= $4.90
(b)
Cost of 5 marbles and 6 stickers
= 5 x 4.90 + 6 x 2.20
= 24.50 + 13.20
= $37.70
Answer(s): (a) $4.90; (b) $37.70