Adam pays $22.30 for 1 marble and 5 stickers.
The marble costs $2.50 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 marbles and 3 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.50
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 2.50 + 5 u
= 6 u + 2.50
6 u + 2.50 = 22.30
6 u = 22.30 - 2.50
6 u = 19.80
1 u = 19.80 ÷ 6 = 3.30
Cost of 1 marble
= 3.30 + 2.50
= $5.80
(b)
Cost of 5 marbles and 3 stickers
= 5 x 5.80 + 3 x 3.30
= 29.00 + 9.90
= $38.90
Answer(s): (a) $5.80; (b) $38.90