If Adam buys 4 beads and 5 marbles, it costs $59.60.
If Adam buys 5 beads and 4 marbles, he will have $1.30 left.
- Find the cost of 1 bead and 1 marble.
- Find the cost of 1 bead.
- Find the cost of 1 marble.
(a)
4 beads + 5 marbles = 59.60 --- (1)
5 beads + 4 marbles = 59.60 - 1.30 = 58.30 --- (2)
(1) + (2)
9 beads + 9 marbles = 117.90 --- (3)
(3)
÷ 9 1 bead + 1 marble = 117.90 ÷ 9 = 13.10 --- (4)
Cost of 1 bead and 1 marble = $13.10
(b)
(4)
x 4 4 beads + 4 marbles = 4 x 13.10 = 52.40 --- (5)
(2) - (5)
5 beads + 4 marbles - 4 beads - 4 marbles = 58.30 - 52.40
5 beads - 4 beads - 4 marbles + 4 marbles = 5.90
1 bead = 5.90
Cost of 1 bead = $5.90
(c)
Substitute 1 bead = 5.90 into (4).
1 bead + 1 marble = 13.10
5.90 + 1 marble = 13.10
1 marble = 13.10 - 5.90 = 7.20
Cost of 1 marble = $7.20
Answer(s): (a) $13.10; (b) $5.90; (c) $7.20