Adam pays $27.70 for 1 marble and 6 stickers.
The marble costs $1.10 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 + 1.10
Cost of 6 stickers
= 6 x 1 u
= 6 u
Total cost of 1 marble and 6 stickers
= 1 u + 1.10 + 6 u
= 7 u + 1.10
7 u + 1.10 = 27.70
7 u = 27.70 - 1.10
7 u = 26.60
1 u = 26.60 ÷ 7 = 3.80
Cost of 1 marble
= 3.80 + 1.10
= $4.90
(b)
Cost of 6 marbles and 8 stickers
= 6 x 4.90 + 8 x 3.80
= 29.40 + 30.40
= $59.80
Answer(s): (a) $4.90; (b) $59.80