Adam pays $27.90 for 1 marble and 4 stickers.
The marble costs $2.40 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 4 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 + 2.40
Cost of 4 stickers
= 4 x 1 u
= 4 u
Total cost of 1 marble and 4 stickers
= 1 u + 2.40 + 4 u
= 5 u + 2.40
5 u + 2.40 = 27.90
5 u = 27.90 - 2.40
5 u = 25.50
1 u = 25.50 ÷ 5 = 5.10
Cost of 1 marble
= 5.10 + 2.40
= $7.50
(b)
Cost of 4 marbles and 3 stickers
= 4 x 7.50 + 3 x 5.10
= 30.00 + 15.30
= $45.30
Answer(s): (a) $7.50; (b) $45.30