Adam pays $27.30 for 1 marble and 4 stickers.
The marble costs $2.80 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 4 marbles and 5 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.80
Cost of 4 stickers
= 4 x 1 u
= 4 u
Total cost of 1 marble and 4 stickers
= 1 u + 2.80 + 4 u
= 5 u + 2.80
5 u + 2.80 = 27.30
5 u = 27.30 - 2.80
5 u = 24.50
1 u = 24.50 ÷ 5 = 4.90
Cost of 1 marble
= 4.90 + 2.80
= $7.70
(b)
Cost of 4 marbles and 5 stickers
= 4 x 7.70 + 5 x 4.90
= 30.80 + 24.50
= $55.30
Answer(s): (a) $7.70; (b) $55.30