Adam pays $43.80 for 1 marble and 8 stickers.
The marble costs $1.50 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 8 marbles and 6 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 8 stickers
= 8 x 1 u
= 8 u
Total cost of 1 marble and 8 stickers
= 1 u + 1.50 + 8 u
= 9 u + 1.50
9 u + 1.50 = 43.80
9 u = 43.80 - 1.50
9 u = 42.30
1 u = 42.30 ÷ 9 = 4.70
Cost of 1 marble
= 4.70 + 1.50
= $6.20
(b)
Cost of 8 marbles and 6 stickers
= 8 x 6.20 + 6 x 4.70
= 49.60 + 28.20
= $77.80
Answer(s): (a) $6.20; (b) $77.80