Adam pays $34.80 for 1 marble and 6 stickers.
The marble costs $1.90 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 6 marbles and 8 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 1.90
Cost of 6 stickers
= 6 x 1 u
= 6 u
Total cost of 1 marble and 6 stickers
= 1 u + 1.90 + 6 u
= 7 u + 1.90
7 u + 1.90 = 34.80
7 u = 34.80 - 1.90
7 u = 32.90
1 u = 32.90 ÷ 7 = 4.70
Cost of 1 marble
= 4.70 + 1.90
= $6.60
(b)
Cost of 6 marbles and 8 stickers
= 6 x 6.60 + 8 x 4.70
= 39.60 + 37.60
= $77.20
Answer(s): (a) $6.60; (b) $77.20