Adam pays $33.20 for 1 marble and 5 stickers.
The marble costs $1.40 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 marbles and 7 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 1.40
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 1.40 + 5 u
= 6 u + 1.40
6 u + 1.40 = 33.20
6 u = 33.20 - 1.40
6 u = 31.80
1 u = 31.80 ÷ 6 = 5.30
Cost of 1 marble
= 5.30 + 1.40
= $6.70
(b)
Cost of 5 marbles and 7 stickers
= 5 x 6.70 + 7 x 5.30
= 33.50 + 37.10
= $70.60
Answer(s): (a) $6.70; (b) $70.60