Adam spends $12.30 on 2 beads and 3 marbles.
A bead costs $2.90 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 + 2.90
Total cost of 2 beads and 3 marbles
= 2(1 u + 2.90) + 3 u
= 2 u + 5.80 + 3 u
= 2 u + 3 u + 5.80
= 5 u + 5.80
5 u + 5.80 = 12.30
5 u = 12.30 - 5.80
5 u = 6.50
1 u = 6.50 ÷ 5 = 1.30
Cost of 1 bead
= 1 u + 2.90
= 1.30 + 2.90
= $4.20
(b)
Cost of 3 beads
= 3 x 4.20
= $12.60
(c)
Cost of 1 marble and 3 beads
= 1.30 + 12.60
= $13.90
(d)
Cost of 3 beads more than 1 marble
= 12.60 - 1.30
= $11.30
Answer(s): (a) $4.20; (b) $12.60; (c) $13.90; (d) $11.30