Adam spends $14.10 on 2 marbles and 3 beads.
A marble costs $2.30 more than 1 bead.
- How much does 1 marble cost?
- How much do 4 marbles cost?
- How much do a bead and 4 marbles cost?
- How much do 4 marbles cost more than 1 bead?
(a)
Let the cheaper item be 1 u.
Cost of 1 bead = 1 u
Cost of 1 marble = 1 u + 2.30
Total cost of 2 marbles and 3 beads
= 2(1 u + 2.30) + 3 u
= 2 u + 4.60 + 3 u
= 2 u + 3 u + 4.60
= 5 u + 4.60
5 u + 4.60 = 14.10
5 u = 14.10 - 4.60
5 u = 9.50
1 u = 9.50 ÷ 5 = 1.90
Cost of 1 marble
= 1 u + 2.30
= 1.90 + 2.30
= $4.20
(b)
Cost of 4 marbles
= 4 x 4.20
= $16.80
(c)
Cost of 1 bead and 4 marbles
= 1.90 + 16.80
= $18.70
(d)
Cost of 4 marbles more than 1 bead
= 16.80 - 1.90
= $14.90
Answer(s): (a) $4.20; (b) $16.80; (c) $18.70; (d) $14.90