Adam spends $14.10 on 3 beads and 4 marbles.
A bead costs $1.90 more than 1 marble.
- How much does 1 bead cost?
- How much do 7 beads cost?
- How much do a marble and 7 beads cost?
- How much do 7 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 + 1.90
Total cost of 3 beads and 4 marbles
= 3(1 u + 1.90) + 4 u
= 3 u + 5.70 + 4 u
= 3 u + 4 u + 5.70
= 7 u + 5.70
7 u + 5.70 = 14.10
7 u = 14.10 - 5.70
7 u = 8.40
1 u = 8.40 ÷ 7 = 1.20
Cost of 1 bead
= 1 u + 1.90
= 1.20 + 1.90
= $3.10
(b)
Cost of 7 beads
= 7 x 3.10
= $21.70
(c)
Cost of 1 marble and 7 beads
= 1.20 + 21.70
= $22.90
(d)
Cost of 7 beads more than 1 marble
= 21.70 - 1.20
= $20.50
Answer(s): (a) $3.10; (b) $21.70; (c) $22.90; (d) $20.50