Adam pays $32.30 for 1 marble and 4 stickers.
The marble costs $1.80 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 4 marbles and 3 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 4 stickers
= 4 x 1 u
= 4 u
Total cost of 1 marble and 4 stickers
= 1 u + 1.80 + 4 u
= 5 u + 1.80
5 u + 1.80 = 32.30
5 u = 32.30 - 1.80
5 u = 30.50
1 u = 30.50 ÷ 5 = 6.10
Cost of 1 marble
= 6.10 + 1.80
= $7.90
(b)
Cost of 4 marbles and 3 stickers
= 4 x 7.90 + 3 x 6.10
= 31.60 + 18.30
= $49.90
Answer(s): (a) $7.90; (b) $49.90