If Adam buys 2 beads and 3 marbles, it costs $24.40.
If Adam buys 3 beads and 2 marbles, he will need another $2.70.
- 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 = 24.40 --- (1)
3 beads + 2 marbles = 24.40 + 2.70 = 27.10 --- (2)
(1) + (2)
5 beads + 5 marbles = 51.50 --- (3)
(3)
÷ 5 1 bead + 1 marble = 51.50 ÷ 5 = 10.30 --- (4)
Cost of 1 bead and 1 marble = $10.30
(b)
3 beads + 2 marbles = 27.10 --- (2)
(4)
x 2 2 beads + 2 marbles = 2 x 10.30 = 20.60 --- (5)
(2) - (5)
3 beads + 2 marbles - 2 beads - 2 marbles = 27.10 - 20.60
3 beads - 2 beads + 2 marbles - 2 marbles = 6.50
1 bead = 6.50
Cost of 1 bead = $6.50
(c)
Substitute 1 bead = 6.50 into (4).
1 bead + 1 marble = 10.30
6.50 + 1 marble = 10.30
1 marble = 10.30 - 6.50 = 3.80
Cost of 1 marble = $3.80
Answer(s): (a) $10.30; (b) $6.50; (c) $3.80