Adam pays $39.10 for 1 marble and 5 stickers.
The marble costs $1.30 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 marbles and 8 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 1.30
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 1.30 + 5 u
= 6 u + 1.30
6 u + 1.30 = 39.10
6 u = 39.10 - 1.30
6 u = 37.80
1 u = 37.80 ÷ 6 = 6.30
Cost of 1 marble
= 6.30 + 1.30
= $7.60
(b)
Cost of 5 marbles and 8 stickers
= 5 x 7.60 + 8 x 6.30
= 38.00 + 50.40
= $88.40
Answer(s): (a) $7.60; (b) $88.40