Adam spends $15.70 on 2 beads and 3 marbles.
A bead costs $1.60 more than 1 marble.
- How much does 1 bead cost?
- How much do 4 beads cost?
- How much do a marble and 4 beads cost?
- How much do 4 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 + 1.60
Total cost of 2 beads and 3 marbles
= 2(1 u + 1.60) + 3 u
= 2 u + 3.20 + 3 u
= 2 u + 3 u + 3.20
= 5 u + 3.20
5 u + 3.20 = 15.70
5 u = 15.70 - 3.20
5 u = 12.50
1 u = 12.50 ÷ 5 = 2.50
Cost of 1 bead
= 1 u + 1.60
= 2.50 + 1.60
= $4.10
(b)
Cost of 4 beads
= 4 x 4.10
= $16.40
(c)
Cost of 1 marble and 4 beads
= 2.50 + 16.40
= $18.90
(d)
Cost of 4 beads more than 1 marble
= 16.40 - 2.50
= $13.90
Answer(s): (a) $4.10; (b) $16.40; (c) $18.90; (d) $13.90