5 beads and 1 marble cost $24.20.
1 bead and 5 marbles cost $15.40.

1. Find the cost of 1 bead and 1 marble.
2. Find the cost of 1 marble.
3. Find the cost of 1 bead.
4. Find the cost of 8 beads and 8 marbles.

(a)
5 beads + 1 marble = 24.20 --- (1)
1 bead + 5 marbles = 15.40 --- (2)

(1) + (2)
6 beads + 6 marbles = 24.20 + 15.40
6 beads + 6 marbles = 39.60 --- (3)

(3) _{÷ 6}
6 beads + 6 marbles = 39.60
1 bead + 1 marble = 39.60 ÷ 6
1 bead + 1 marble = 6.60 --- (4)

(b)
(2) - (4)
(1 bead + 5 marbles) - (1 bead + 1 marble) = 15.40 - 6.60
1 bead - 1 bead + 5 marbles - 1 marble = 8.80
4 marbles = 8.80
1 marble = 8.80 ÷ 4 = 2.20

Cost of 1 marble = $2.20

(c)
Substitute 1 marble = 2.20 into (4).
1 bead + 1 marble = 6.60
1 bead + 2.20 = 6.60
1 bead = 6.60 - 2.20 = 4.40

Cost of 1 bead = $4.40

(d)
(4) _{x 8}
1 bead + 1 marble = 6.60
8 x (1 bead + 1 marble) = 8 x 6.60
8 beads + 8 marbles = 52.80

Cost of 8 beads and 8 marbles = $52.80

Answer(s): (a) $6.60; (b) $2.20; (c) $4.40; (d) $52.80