If Adam buys 5 beads and 6 marbles, it costs $65.30.
If Adam buys 6 beads and 5 marbles, he will have $1.90 left.

1. Find the cost of 1 bead and 1 marble.
2. Find the cost of 1 bead.
3. Find the cost of 1 marble.

(a)
5 beads + 6 marbles = 65.30 --- (1)
6 beads + 5 marbles = 65.30 - 1.90 = 63.40 --- (2)

(1) + (2)
11 beads + 11 marbles = 128.70 --- (3)

(3) _{÷ 11}
1 bead + 1 marble = 128.70 ÷ 11 = 11.70 --- (4)

Cost of 1 bead and 1 marble = $11.70

(b)
(4) _{x 5}
5 beads + 5 marbles = 5 x 11.70 = 58.50 --- (5)

(2) - (5)
6 beads + 5 marbles - 5 beads - 5 marbles = 63.40 - 58.50
6 beads - 5 beads - 5 marbles + 5 marbles = 4.90
1 bead = 4.90

Cost of 1 bead = $4.90

(c)
Substitute 1 bead = 4.90 into (4).

1 bead + 1 marble = 11.70
4.90 + 1 marble = 11.70
1 marble = 11.70 - 4.90 = 6.80

Cost of 1 marble = $6.80

Answer(s): (a) $11.70; (b) $4.90; (c) $6.80