Adam pays $30.70 for 1 marble and 5 stickers.
The marble costs $1.90 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 marbles and 2 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 1.90
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 1.90 + 5 u
= 6 u + 1.90
6 u + 1.90 = 30.70
6 u = 30.70 - 1.90
6 u = 28.80
1 u = 28.80 ÷ 6 = 4.80
Cost of 1 marble
= 4.80 + 1.90
= $6.70
(b)
Cost of 5 marbles and 2 stickers
= 5 x 6.70 + 2 x 4.80
= 33.50 + 9.60
= $43.10
Answer(s): (a) $6.70; (b) $43.10