Adam pays $41.40 for 1 marble and 6 stickers.
The marble costs $2.90 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 6 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 + 2.90
Cost of 6 stickers
= 6 x 1 u
= 6 u
Total cost of 1 marble and 6 stickers
= 1 u + 2.90 + 6 u
= 7 u + 2.90
7 u + 2.90 = 41.40
7 u = 41.40 - 2.90
7 u = 38.50
1 u = 38.50 ÷ 7 = 5.50
Cost of 1 marble
= 5.50 + 2.90
= $8.40
(b)
Cost of 6 marbles and 4 stickers
= 6 x 8.40 + 4 x 5.50
= 50.40 + 22.00
= $72.40
Answer(s): (a) $8.40; (b) $72.40