Adam pays $32.10 for 1 marble and 6 stickers.
The marble costs $2.70 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 + 2.70
Cost of 6 stickers
= 6 x 1 u
= 6 u
Total cost of 1 marble and 6 stickers
= 1 u + 2.70 + 6 u
= 7 u + 2.70
7 u + 2.70 = 32.10
7 u = 32.10 - 2.70
7 u = 29.40
1 u = 29.40 ÷ 7 = 4.20
Cost of 1 marble
= 4.20 + 2.70
= $6.90
(b)
Cost of 6 marbles and 2 stickers
= 6 x 6.90 + 2 x 4.20
= 41.40 + 8.40
= $49.80
Answer(s): (a) $6.90; (b) $49.80