Adam pays $42.90 for 1 marble and 5 stickers.
The marble costs $1.50 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 + 1.50
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 1.50 + 5 u
= 6 u + 1.50
6 u + 1.50 = 42.90
6 u = 42.90 - 1.50
6 u = 41.40
1 u = 41.40 ÷ 6 = 6.90
Cost of 1 marble
= 6.90 + 1.50
= $8.40
(b)
Cost of 5 marbles and 3 stickers
= 5 x 8.40 + 3 x 6.90
= 42.00 + 20.70
= $62.70
Answer(s): (a) $8.40; (b) $62.70