Adam spends $14.30 on 2 marbles and 3 beads.
A marble costs $1.40 more than 1 bead.
- How much does 1 marble cost?
- How much do 7 marbles cost?
- How much do a bead and 7 marbles cost?
- How much do 7 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 + 1.40
Total cost of 2 marbles and 3 beads
= 2(1 u + 1.40) + 3 u
= 2 u + 2.80 + 3 u
= 2 u + 3 u + 2.80
= 5 u + 2.80
5 u + 2.80 = 14.30
5 u = 14.30 - 2.80
5 u = 11.50
1 u = 11.50 ÷ 5 = 2.30
Cost of 1 marble
= 1 u + 1.40
= 2.30 + 1.40
= $3.70
(b)
Cost of 7 marbles
= 7 x 3.70
= $25.90
(c)
Cost of 1 bead and 7 marbles
= 2.30 + 25.90
= $28.20
(d)
Cost of 7 marbles more than 1 bead
= 25.90 - 2.30
= $23.60
Answer(s): (a) $3.70; (b) $25.90; (c) $28.20; (d) $23.60
