Adam pays $42.60 for 1 marble and 5 stickers.
The marble costs $1.20 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 marbles and 3 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 1.20
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 1.20 + 5 u
= 6 u + 1.20
6 u + 1.20 = 42.60
6 u = 42.60 - 1.20
6 u = 41.40
1 u = 41.40 ÷ 6 = 6.90
Cost of 1 marble
= 6.90 + 1.20
= $8.10
(b)
Cost of 5 marbles and 3 stickers
= 5 x 8.10 + 3 x 6.90
= 40.50 + 20.70
= $61.20
Answer(s): (a) $8.10; (b) $61.20