If Adam buys 5 beads and 6 marbles, it costs $62.10.
If Adam buys 6 beads and 5 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)
5 beads + 6 marbles = 62.10 --- (1)
6 beads + 5 marbles = 62.10 - 4.30 = 57.80 --- (2)
(1) + (2)
11 beads + 11 marbles = 119.90 --- (3)
(3)
÷ 11 1 bead + 1 marble = 119.90 ÷ 11 = 10.90 --- (4)
Cost of 1 bead and 1 marble = $10.90
(b)
(4)
x 5 5 beads + 5 marbles = 5 x 10.90 = 54.50 --- (5)
(2) - (5)
6 beads + 5 marbles - 5 beads - 5 marbles = 57.80 - 54.50
6 beads - 5 beads - 5 marbles + 5 marbles = 3.30
1 bead = 3.30
Cost of 1 bead = $3.30
(c)
Substitute 1 bead = 3.30 into (4).
1 bead + 1 marble = 10.90
3.30 + 1 marble = 10.90
1 marble = 10.90 - 3.30 = 7.60
Cost of 1 marble = $7.60
Answer(s): (a) $10.90; (b) $3.30; (c) $7.60