Adam pays $38.60 for 1 marble and 6 stickers.
The marble costs $1.50 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 6 marbles and 2 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 1.50
Cost of 6 stickers
= 6 x 1 u
= 6 u
Total cost of 1 marble and 6 stickers
= 1 u + 1.50 + 6 u
= 7 u + 1.50
7 u + 1.50 = 38.60
7 u = 38.60 - 1.50
7 u = 37.10
1 u = 37.10 ÷ 7 = 5.30
Cost of 1 marble
= 5.30 + 1.50
= $6.80
(b)
Cost of 6 marbles and 2 stickers
= 6 x 6.80 + 2 x 5.30
= 40.80 + 10.60
= $51.40
Answer(s): (a) $6.80; (b) $51.40