If Adam buys 5 beads and 6 marbles, it costs $66.30.
If Adam buys 6 beads and 5 marbles, he will have $7.20 left.
- Find the cost of 1 bead and 1 marble.
- Find the cost of 1 bead.
- Find the cost of 1 marble.
(a)
5 beads + 6 marbles = 66.30 --- (1)
6 beads + 5 marbles = 66.30 - 7.20 = 59.10 --- (2)
(1) + (2)
11 beads + 11 marbles = 125.40 --- (3)
(3)
÷ 11 1 bead + 1 marble = 125.40 ÷ 11 = 11.40 --- (4)
Cost of 1 bead and 1 marble = $11.40
(b)
(4)
x 5 5 beads + 5 marbles = 5 x 11.40 = 570 --- (5)
(2) - (5)
6 beads + 5 marbles - 5 beads - 5 marbles = 59.10 - 570
6 beads - 5 beads - 5 marbles + 5 marbles = 2.10
1 bead = 2.10
Cost of 1 bead = $2.10
(c)
Substitute 1 bead = 2.10 into (4).
1 bead + 1 marble = 11.40
2.10 + 1 marble = 11.40
1 marble = 11.40 - 2.10 = 9.30
Cost of 1 marble = $9.30
Answer(s): (a) $11.40; (b) $2.10; (c) $9.30