Adam spends $13.30 on 4 beads and 5 marbles.
A bead costs $2.20 more than 1 marble.
- How much does 1 bead cost?
- How much do 8 beads cost?
- How much do a marble and 8 beads cost?
- How much do 8 beads cost more than 1 marble?
(a)
Let the cheaper item be 1 u.
Cost of 1 marble = 1 u
Cost of 1 bead = 1 u + 2.20
Total cost of 4 beads and 5 marbles
= 4(1 u + 2.20) + 5 u
= 4 u + 8.80 + 5 u
= 4 u + 5 u + 8.80
= 9 u + 8.80
9 u + 8.80 = 13.30
9 u = 13.30 - 8.80
9 u = 4.50
1 u = 4.50 ÷ 9 = 0.50
Cost of 1 bead
= 1 u + 2.20
= 0.50 + 2.20
= $2.70
(b)
Cost of 8 beads
= 8 x 2.70
= $21.60
(c)
Cost of 1 marble and 8 beads
= 0.50 + 21.60
= $22.10
(d)
Cost of 8 beads more than 1 marble
= 21.60 - 0.50
= $21.10
Answer(s): (a) $2.70; (b) $21.60; (c) $22.10; (d) $21.10
