Adam spends $14.90 on 2 marbles and 3 beads.
A marble costs $1.20 more than 1 bead.
- How much does 1 marble cost?
- How much do 8 marbles cost?
- How much do a bead and 8 marbles cost?
- How much do 8 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 + 1.20
Total cost of 2 marbles and 3 beads
= 2(1 u + 1.20) + 3 u
= 2 u + 2.40 + 3 u
= 2 u + 3 u + 2.40
= 5 u + 2.40
5 u + 2.40 = 14.90
5 u = 14.90 - 2.40
5 u = 12.50
1 u = 12.50 ÷ 5 = 2.50
Cost of 1 marble
= 1 u + 1.20
= 2.50 + 1.20
= $3.70
(b)
Cost of 8 marbles
= 8 x 3.70
= $29.60
(c)
Cost of 1 bead and 8 marbles
= 2.50 + 29.60
= $32.10
(d)
Cost of 8 marbles more than 1 bead
= 29.60 - 2.50
= $27.10
Answer(s): (a) $3.70; (b) $29.60; (c) $32.10; (d) $27.10