Adam pays $24.90 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 5 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 = 24.90
9 u = 24.90 - 1.50
9 u = 23.40
1 u = 23.40 ÷ 9 = 2.60
Cost of 1 marble
= 2.60 + 1.50
= $4.10
(b)
Cost of 8 marbles and 5 stickers
= 8 x 4.10 + 5 x 2.60
= 32.80 + 13.00
= $45.80
Answer(s): (a) $4.10; (b) $45.80