If Adam buys 5 beads and 6 marbles, it costs $46.20.
If Adam buys 6 beads and 5 marbles, he will have $5.50 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 = 46.20 --- (1)
6 beads + 5 marbles = 46.20 - 5.50 = 40.70 --- (2)
(1) + (2)
11 beads + 11 marbles = 86.90 --- (3)
(3)
÷ 11 1 bead + 1 marble = 86.90 ÷ 11 = 7.90 --- (4)
Cost of 1 bead and 1 marble = $7.90
(b)
(4)
x 5 5 beads + 5 marbles = 5 x 7.90 = 39.50 --- (5)
(2) - (5)
6 beads + 5 marbles - 5 beads - 5 marbles = 40.70 - 39.50
6 beads - 5 beads - 5 marbles + 5 marbles = 1.20
1 bead = 1.20
Cost of 1 bead = $1.20
(c)
Substitute 1 bead = 1.20 into (4).
1 bead + 1 marble = 7.90
1.20 + 1 marble = 7.90
1 marble = 7.90 - 1.20 = 6.70
Cost of 1 marble = $6.70
Answer(s): (a) $7.90; (b) $1.20; (c) $6.70