Adam pays $36.90 for 1 marble and 5 stickers.
The marble costs $2.10 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 marbles and 4 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.10
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 2.10 + 5 u
= 6 u + 2.10
6 u + 2.10 = 36.90
6 u = 36.90 - 2.10
6 u = 34.80
1 u = 34.80 ÷ 6 = 5.80
Cost of 1 marble
= 5.80 + 2.10
= $7.90
(b)
Cost of 5 marbles and 4 stickers
= 5 x 7.90 + 4 x 5.80
= 39.50 + 23.20
= $62.70
Answer(s): (a) $7.90; (b) $62.70