If Adam buys 2 beads and 3 marbles, it costs $31.60.
If Adam buys 3 beads and 2 marbles, he will have $8.70 left.
- Find the cost of 1 bead and 1 marble.
- Find the cost of 1 bead.
- Find the cost of 1 marble.
(a)
2 beads + 3 marbles = 31.60 --- (1)
3 beads + 2 marbles = 31.60 - 8.70 = 22.90 --- (2)
(1) + (2)
5 beads + 5 marbles = 54.50 --- (3)
(3)
÷ 5 1 bead + 1 marble = 54.50 ÷ 5 = 10.90 --- (4)
Cost of 1 bead and 1 marble = $10.90
(b)
(4)
x 2 2 beads + 2 marbles = 2 x 10.90 = 21.80 --- (5)
(2) - (5)
3 beads + 2 marbles - 2 beads - 2 marbles = 22.90 - 21.80
3 beads - 2 beads - 2 marbles + 2 marbles = 1.10
1 bead = 1.10
Cost of 1 bead = $1.10
(c)
Substitute 1 bead = 1.10 into (4).
1 bead + 1 marble = 10.90
1.10 + 1 marble = 10.90
1 marble = 10.90 - 1.10 = 9.80
Cost of 1 marble = $9.80
Answer(s): (a) $10.90; (b) $1.10; (c) $9.80