Adam spends $14.10 on 2 marbles and 3 beads.
A marble costs $1.30 more than 1 bead.
- How much does 1 marble cost?
- How much do 3 marbles cost?
- How much do a bead and 3 marbles cost?
- How much do 3 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 + 1.30
Total cost of 2 marbles and 3 beads
= 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 = 14.10
5 u = 14.10 - 2.60
5 u = 11.50
1 u = 11.50 ÷ 5 = 2.30
Cost of 1 marble
= 1 u + 1.30
= 2.30 + 1.30
= $3.60
(b)
Cost of 3 marbles
= 3 x 3.60
= $10.80
(c)
Cost of 1 bead and 3 marbles
= 2.30 + 10.80
= $13.10
(d)
Cost of 3 marbles more than 1 bead
= 10.80 - 2.30
= $8.50
Answer(s): (a) $3.60; (b) $10.80; (c) $13.10; (d) $8.50