Adam pays $40.90 for 1 marble and 5 stickers.
The marble costs $1.30 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 + 1.30
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 1.30 + 5 u
= 6 u + 1.30
6 u + 1.30 = 40.90
6 u = 40.90 - 1.30
6 u = 39.60
1 u = 39.60 ÷ 6 = 6.60
Cost of 1 marble
= 6.60 + 1.30
= $7.90
(b)
Cost of 5 marbles and 6 stickers
= 5 x 7.90 + 6 x 6.60
= 39.50 + 39.60
= $79.10
Answer(s): (a) $7.90; (b) $79.10