Adam pays $19.50 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 4 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 = 19.50
6 u = 19.50 - 2.70
6 u = 16.80
1 u = 16.80 ÷ 6 = 2.80
Cost of 1 marble
= 2.80 + 2.70
= $5.50
(b)
Cost of 5 marbles and 4 stickers
= 5 x 5.50 + 4 x 2.80
= 27.50 + 11.20
= $38.70
Answer(s): (a) $5.50; (b) $38.70