Adam pays $32.70 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 2 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 = 32.70
7 u = 32.70 - 1.90
7 u = 30.80
1 u = 30.80 ÷ 7 = 4.40
Cost of 1 marble
= 4.40 + 1.90
= $6.30
(b)
Cost of 6 marbles and 2 stickers
= 6 x 6.30 + 2 x 4.40
= 37.80 + 8.80
= $46.60
Answer(s): (a) $6.30; (b) $46.60