Adam pays $44.30 for 1 marble and 7 stickers.
The marble costs $1.90 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 7 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 + 1.90
Cost of 7 stickers
= 7 x 1 u
= 7 u
Total cost of 1 marble and 7 stickers
= 1 u + 1.90 + 7 u
= 8 u + 1.90
8 u + 1.90 = 44.30
8 u = 44.30 - 1.90
8 u = 42.40
1 u = 42.40 ÷ 8 = 5.30
Cost of 1 marble
= 5.30 + 1.90
= $7.20
(b)
Cost of 7 marbles and 5 stickers
= 7 x 7.20 + 5 x 5.30
= 50.40 + 26.50
= $76.90
Answer(s): (a) $7.20; (b) $76.90