If Adam buys 5 beads and 6 marbles, it costs $56.90.
If Adam buys 6 beads and 5 marbles, he will have $60 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 = 56.90 --- (1)
6 beads + 5 marbles = 56.90 - 60 = 50.90 --- (2)
(1) + (2)
11 beads + 11 marbles = 107.80 --- (3)
(3)
÷ 11 1 bead + 1 marble = 107.80 ÷ 11 = 9.80 --- (4)
Cost of 1 bead and 1 marble = $9.80
(b)
(4)
x 5 5 beads + 5 marbles = 5 x 9.80 = 490 --- (5)
(2) - (5)
6 beads + 5 marbles - 5 beads - 5 marbles = 50.90 - 490
6 beads - 5 beads - 5 marbles + 5 marbles = 1.90
1 bead = 1.90
Cost of 1 bead = $1.90
(c)
Substitute 1 bead = 1.90 into (4).
1 bead + 1 marble = 9.80
1.90 + 1 marble = 9.80
1 marble = 9.80 - 1.90 = 7.90
Cost of 1 marble = $7.90
Answer(s): (a) $9.80; (b) $1.90; (c) $7.90