Adam spends $13.10 on 2 beads and 3 marbles.
A bead costs $1.30 more than 1 marble.
- How much does 1 bead cost?
- How much do 3 beads cost?
- How much do a marble and 3 beads cost?
- How much do 3 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 + 1.30
Total cost of 2 beads and 3 marbles
= 2(1 u + 1.30) + 3 u
= 2 u + 2.60 + 3 u
= 2 u + 3 u + 2.60
= 5 u + 2.60
5 u + 2.60 = 13.10
5 u = 13.10 - 2.60
5 u = 10.50
1 u = 10.50 ÷ 5 = 2.10
Cost of 1 bead
= 1 u + 1.30
= 2.10 + 1.30
= $3.40
(b)
Cost of 3 beads
= 3 x 3.40
= $10.20
(c)
Cost of 1 marble and 3 beads
= 2.10 + 10.20
= $12.30
(d)
Cost of 3 beads more than 1 marble
= 10.20 - 2.10
= $8.10
Answer(s): (a) $3.40; (b) $10.20; (c) $12.30; (d) $8.10