Adam spends $15.60 on 3 beads and 4 marbles.
A bead costs $1.70 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 + 1.70
Total cost of 3 beads and 4 marbles
= 3(1 u + 1.70) + 4 u
= 3 u + 5.10 + 4 u
= 3 u + 4 u + 5.10
= 7 u + 5.10
7 u + 5.10 = 15.60
7 u = 15.60 - 5.10
7 u = 10.50
1 u = 10.50 ÷ 7 = 1.50
Cost of 1 bead
= 1 u + 1.70
= 1.50 + 1.70
= $3.20
(b)
Cost of 8 beads
= 8 x 3.20
= $25.60
(c)
Cost of 1 marble and 8 beads
= 1.50 + 25.60
= $27.10
(d)
Cost of 8 beads more than 1 marble
= 25.60 - 1.50
= $24.10
Answer(s): (a) $3.20; (b) $25.60; (c) $27.10; (d) $24.10
