Adam pays $22.20 for 1 marble and 5 stickers.
The marble costs $1.80 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 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 + 1.80
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 1.80 + 5 u
= 6 u + 1.80
6 u + 1.80 = 22.20
6 u = 22.20 - 1.80
6 u = 20.40
1 u = 20.40 ÷ 6 = 3.40
Cost of 1 marble
= 3.40 + 1.80
= $5.20
(b)
Cost of 5 marbles and 6 stickers
= 5 x 5.20 + 6 x 3.40
= 26.00 + 20.40
= $46.40
Answer(s): (a) $5.20; (b) $46.40