If Adam buys 5 marbles and 6 beads, it costs $54.80.
If Adam buys 6 marbles and 5 beads, he will have $40 left.

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

(a)
5 marbles + 6 beads = 54.80 --- (1)
6 marbles + 5 beads = 54.80 - 40 = 50.80 --- (2)

(1) + (2)
11 marbles + 11 beads = 105.60 --- (3)

(3) _{÷ 11}
1 marble + 1 bead = 105.60 ÷ 11 = 9.60 --- (4)

Cost of 1 marble and 1 bead = $9.60

(b)
(4) _{x 5}
5 marbles + 5 beads = 5 x 9.60 = 480 --- (5)

(2) - (5)
6 marbles + 5 beads - 5 marbles - 5 beads = 50.80 - 480
6 marbles - 5 marbles - 5 beads + 5 beads = 2.80
1 marble = 2.80

Cost of 1 marble = $2.80

(c)
Substitute 1 marble = 2.80 into (4).

1 marble + 1 bead = 9.60
2.80 + 1 bead = 9.60
1 bead = 9.60 - 2.80 = 6.80

Cost of 1 bead = $6.80

Answer(s): (a) $9.60; (b) $2.80; (c) $6.80