Adam pays $38.90 for 1 marble and 5 stickers.
The marble costs $2.30 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 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 + 2.30
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 2.30 + 5 u
= 6 u + 2.30
6 u + 2.30 = 38.90
6 u = 38.90 - 2.30
6 u = 36.60
1 u = 36.60 ÷ 6 = 6.10
Cost of 1 marble
= 6.10 + 2.30
= $8.40
(b)
Cost of 5 marbles and 3 stickers
= 5 x 8.40 + 3 x 6.10
= 42.00 + 18.30
= $60.30
Answer(s): (a) $8.40; (b) $60.30