If Adam buys 2 beads and 3 marbles, it costs $27.60.
If Adam buys 3 beads and 2 marbles, he will have $2.70 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 = 27.60 --- (1)
3 beads + 2 marbles = 27.60 - 2.70 = 24.90 --- (2)
(1) + (2)
5 beads + 5 marbles = 52.50 --- (3)
(3)
÷ 5 1 bead + 1 marble = 52.50 ÷ 5 = 10.50 --- (4)
Cost of 1 bead and 1 marble = $10.50
(b)
(4)
x 2 2 beads + 2 marbles = 2 x 10.50 = 210 --- (5)
(2) - (5)
3 beads + 2 marbles - 2 beads - 2 marbles = 24.90 - 210
3 beads - 2 beads - 2 marbles + 2 marbles = 3.90
1 bead = 3.90
Cost of 1 bead = $3.90
(c)
Substitute 1 bead = 3.90 into (4).
1 bead + 1 marble = 10.50
3.90 + 1 marble = 10.50
1 marble = 10.50 - 3.90 = 6.60
Cost of 1 marble = $6.60
Answer(s): (a) $10.50; (b) $3.90; (c) $6.60