If Adam buys 2 beads and 3 marbles, it costs $25.80.
If Adam buys 3 beads and 2 marbles, he will need another $1.90.
- 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 = 25.80 --- (1)
3 beads + 2 marbles = 25.80 + 1.90 = 27.70 --- (2)
(1) + (2)
5 beads + 5 marbles = 53.50 --- (3)
(3)
÷ 5 1 bead + 1 marble = 53.50 ÷ 5 = 10.70 --- (4)
Cost of 1 bead and 1 marble = $10.70
(b)
3 beads + 2 marbles = 27.70 --- (2)
(4)
x 2 2 beads + 2 marbles = 2 x 10.70 = 21.40 --- (5)
(2) - (5)
3 beads + 2 marbles - 2 beads - 2 marbles = 27.70 - 21.40
3 beads - 2 beads + 2 marbles - 2 marbles = 6.30
1 bead = 6.30
Cost of 1 bead = $6.30
(c)
Substitute 1 bead = 6.30 into (4).
1 bead + 1 marble = 10.70
6.30 + 1 marble = 10.70
1 marble = 10.70 - 6.30 = 4.40
Cost of 1 marble = $4.40
Answer(s): (a) $10.70; (b) $6.30; (c) $4.40