Adam pays $35.90 for 1 marble and 7 stickers.
The marble costs $1.50 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 7 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 + 1.50
Cost of 7 stickers
= 7 x 1 u
= 7 u
Total cost of 1 marble and 7 stickers
= 1 u + 1.50 + 7 u
= 8 u + 1.50
8 u + 1.50 = 35.90
8 u = 35.90 - 1.50
8 u = 34.40
1 u = 34.40 ÷ 8 = 4.30
Cost of 1 marble
= 4.30 + 1.50
= $5.80
(b)
Cost of 7 marbles and 2 stickers
= 7 x 5.80 + 2 x 4.30
= 40.60 + 8.60
= $49.20
Answer(s): (a) $5.80; (b) $49.20