If Adam buys 5 stickers and 6 marbles, it costs $75.10.
If Adam buys 6 stickers and 5 marbles, he will have $3.90 left.
- Find the cost of 1 sticker and 1 marble.
- Find the cost of 1 sticker.
- Find the cost of 1 marble.
(a)
5 stickers + 6 marbles = 75.10 --- (1)
6 stickers + 5 marbles = 75.10 - 3.90 = 71.20 --- (2)
(1) + (2)
11 stickers + 11 marbles = 146.30 --- (3)
(3)
÷ 11 1 sticker + 1 marble = 146.30 ÷ 11 = 13.30 --- (4)
Cost of 1 sticker and 1 marble = $13.30
(b)
(4)
x 5 5 stickers + 5 marbles = 5 x 13.30 = 66.50 --- (5)
(2) - (5)
6 stickers + 5 marbles - 5 stickers - 5 marbles = 71.20 - 66.50
6 stickers - 5 stickers - 5 marbles + 5 marbles = 4.70
1 sticker = 4.70
Cost of 1 sticker = $4.70
(c)
Substitute 1 sticker = 4.70 into (4).
1 sticker + 1 marble = 13.30
4.70 + 1 marble = 13.30
1 marble = 13.30 - 4.70 = 8.60
Cost of 1 marble = $8.60
Answer(s): (a) $13.30; (b) $4.70; (c) $8.60