Adam pays $37.80 for 1 marble and 5 stickers.
The marble costs $2.40 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 + 2.40
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 2.40 + 5 u
= 6 u + 2.40
6 u + 2.40 = 37.80
6 u = 37.80 - 2.40
6 u = 35.40
1 u = 35.40 ÷ 6 = 5.90
Cost of 1 marble
= 5.90 + 2.40
= $8.30
(b)
Cost of 5 marbles and 4 stickers
= 5 x 8.30 + 4 x 5.90
= 41.50 + 23.60
= $65.10
Answer(s): (a) $8.30; (b) $65.10