Adam pays $19.20 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 8 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 = 19.20
6 u = 19.20 - 1.80
6 u = 17.40
1 u = 17.40 ÷ 6 = 2.90
Cost of 1 marble
= 2.90 + 1.80
= $4.70
(b)
Cost of 5 marbles and 8 stickers
= 5 x 4.70 + 8 x 2.90
= 23.50 + 23.20
= $46.70
Answer(s): (a) $4.70; (b) $46.70