Adam pays $20.90 for 1 marble and 5 stickers.
The marble costs $1.10 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 + 1.10
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 1.10 + 5 u
= 6 u + 1.10
6 u + 1.10 = 20.90
6 u = 20.90 - 1.10
6 u = 19.80
1 u = 19.80 ÷ 6 = 3.30
Cost of 1 marble
= 3.30 + 1.10
= $4.40
(b)
Cost of 5 marbles and 6 stickers
= 5 x 4.40 + 6 x 3.30
= 22.00 + 19.80
= $41.80
Answer(s): (a) $4.40; (b) $41.80