Adam spends $14.70 on 4 beads and 5 marbles.
A bead costs $2.10 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 + 2.10
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 = 14.70
9 u = 14.70 - 8.40
9 u = 6.30
1 u = 6.30 ÷ 9 = 0.70
Cost of 1 bead
= 1 u + 2.10
= 0.70 + 2.10
= $2.80
(b)
Cost of 8 beads
= 8 x 2.80
= $22.40
(c)
Cost of 1 marble and 8 beads
= 0.70 + 22.40
= $23.10
(d)
Cost of 8 beads more than 1 marble
= 22.40 - 0.70
= $21.70
Answer(s): (a) $2.80; (b) $22.40; (c) $23.10; (d) $21.70