Adam spends $13.80 on 4 beads and 5 marbles.
A bead costs $2.10 more than 1 marble.
- How much does 1 bead cost?
- How much do 5 beads cost?
- How much do a marble and 5 beads cost?
- How much do 5 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 + 2.10
Total cost of 4 beads and 5 marbles
= 4(1 u + 2.10) + 5 u
= 4 u + 8.40 + 5 u
= 4 u + 5 u + 8.40
= 9 u + 8.40
9 u + 8.40 = 13.80
9 u = 13.80 - 8.40
9 u = 5.40
1 u = 5.40 ÷ 9 = 0.60
Cost of 1 bead
= 1 u + 2.10
= 0.60 + 2.10
= $2.70
(b)
Cost of 5 beads
= 5 x 2.70
= $13.50
(c)
Cost of 1 marble and 5 beads
= 0.60 + 13.50
= $14.10
(d)
Cost of 5 beads more than 1 marble
= 13.50 - 0.60
= $12.90
Answer(s): (a) $2.70; (b) $13.50; (c) $14.10; (d) $12.90
