Adam pays $21.10 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 4 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 = 21.10
6 u = 21.10 - 1.90
6 u = 19.20
1 u = 19.20 ÷ 6 = 3.20
Cost of 1 marble
= 3.20 + 1.90
= $5.10
(b)
Cost of 5 marbles and 4 stickers
= 5 x 5.10 + 4 x 3.20
= 25.50 + 12.80
= $38.30
Answer(s): (a) $5.10; (b) $38.30