If Adam buys 2 beads and 3 marbles, it costs $23.90.
If Adam buys 3 beads and 2 marbles, he will have $4.30 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 = 23.90 --- (1)
3 beads + 2 marbles = 23.90 - 4.30 = 19.60 --- (2)
(1) + (2)
5 beads + 5 marbles = 43.50 --- (3)
(3)
÷ 5 1 bead + 1 marble = 43.50 ÷ 5 = 8.70 --- (4)
Cost of 1 bead and 1 marble = $8.70
(b)
(4)
x 2 2 beads + 2 marbles = 2 x 8.70 = 17.40 --- (5)
(2) - (5)
3 beads + 2 marbles - 2 beads - 2 marbles = 19.60 - 17.40
3 beads - 2 beads - 2 marbles + 2 marbles = 2.20
1 bead = 2.20
Cost of 1 bead = $2.20
(c)
Substitute 1 bead = 2.20 into (4).
1 bead + 1 marble = 8.70
2.20 + 1 marble = 8.70
1 marble = 8.70 - 2.20 = 6.50
Cost of 1 marble = $6.50
Answer(s): (a) $8.70; (b) $2.20; (c) $6.50