Adam spends $12.10 on 3 beads and 4 marbles.
A bead costs $2.40 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 + 2.40
Total cost of 3 beads and 4 marbles
= 3(1 u + 2.40) + 4 u
= 3 u + 7.20 + 4 u
= 3 u + 4 u + 7.20
= 7 u + 7.20
7 u + 7.20 = 12.10
7 u = 12.10 - 7.20
7 u = 4.90
1 u = 4.90 ÷ 7 = 0.70
Cost of 1 bead
= 1 u + 2.40
= 0.70 + 2.40
= $3.10
(b)
Cost of 8 beads
= 8 x 3.10
= $24.80
(c)
Cost of 1 marble and 8 beads
= 0.70 + 24.80
= $25.50
(d)
Cost of 8 beads more than 1 marble
= 24.80 - 0.70
= $24.10
Answer(s): (a) $3.10; (b) $24.80; (c) $25.50; (d) $24.10