Adam spends $13.70 on 2 beads and 3 marbles.
A bead costs $1.10 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 + 1.10
Total cost of 2 beads and 3 marbles
= 2(1 u + 1.10) + 3 u
= 2 u + 2.20 + 3 u
= 2 u + 3 u + 2.20
= 5 u + 2.20
5 u + 2.20 = 13.70
5 u = 13.70 - 2.20
5 u = 11.50
1 u = 11.50 ÷ 5 = 2.30
Cost of 1 bead
= 1 u + 1.10
= 2.30 + 1.10
= $3.40
(b)
Cost of 3 beads
= 3 x 3.40
= $10.20
(c)
Cost of 1 marble and 3 beads
= 2.30 + 10.20
= $12.50
(d)
Cost of 3 beads more than 1 marble
= 10.20 - 2.30
= $7.90
Answer(s): (a) $3.40; (b) $10.20; (c) $12.50; (d) $7.90