Adam pays $27.80 for 1 marble and 4 stickers.
The marble costs $2.30 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 + 2.30
Cost of 4 stickers
= 4 x 1 u
= 4 u
Total cost of 1 marble and 4 stickers
= 1 u + 2.30 + 4 u
= 5 u + 2.30
5 u + 2.30 = 27.80
5 u = 27.80 - 2.30
5 u = 25.50
1 u = 25.50 ÷ 5 = 5.10
Cost of 1 marble
= 5.10 + 2.30
= $7.40
(b)
Cost of 4 marbles and 5 stickers
= 4 x 7.40 + 5 x 5.10
= 29.60 + 25.50
= $55.10
Answer(s): (a) $7.40; (b) $55.10