Adam pays $40.40 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 = 40.40
7 u = 40.40 - 1.90
7 u = 38.50
1 u = 38.50 ÷ 7 = 5.50
Cost of 1 marble
= 5.50 + 1.90
= $7.40
(b)
Cost of 6 marbles and 8 stickers
= 6 x 7.40 + 8 x 5.50
= 44.40 + 44.00
= $88.40
Answer(s): (a) $7.40; (b) $88.40