Adam pays $15.60 for 1 marble and 5 stickers.
The marble costs $1.80 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 + 1.80
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 1.80 + 5 u
= 6 u + 1.80
6 u + 1.80 = 15.60
6 u = 15.60 - 1.80
6 u = 13.80
1 u = 13.80 ÷ 6 = 2.30
Cost of 1 marble
= 2.30 + 1.80
= $4.10
(b)
Cost of 5 marbles and 4 stickers
= 5 x 4.10 + 4 x 2.30
= 20.50 + 9.20
= $29.70
Answer(s): (a) $4.10; (b) $29.70