If Adam buys 2 beads and 3 marbles, it costs $36.70.
If Adam buys 3 beads and 2 marbles, he will have $5.90 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 = 36.70 --- (1)
3 beads + 2 marbles = 36.70 - 5.90 = 30.80 --- (2)
(1) + (2)
5 beads + 5 marbles = 67.50 --- (3)
(3)
÷ 5 1 bead + 1 marble = 67.50 ÷ 5 = 13.50 --- (4)
Cost of 1 bead and 1 marble = $13.50
(b)
(4)
x 2 2 beads + 2 marbles = 2 x 13.50 = 270 --- (5)
(2) - (5)
3 beads + 2 marbles - 2 beads - 2 marbles = 30.80 - 270
3 beads - 2 beads - 2 marbles + 2 marbles = 3.80
1 bead = 3.80
Cost of 1 bead = $3.80
(c)
Substitute 1 bead = 3.80 into (4).
1 bead + 1 marble = 13.50
3.80 + 1 marble = 13.50
1 marble = 13.50 - 3.80 = 9.70
Cost of 1 marble = $9.70
Answer(s): (a) $13.50; (b) $3.80; (c) $9.70