Adam spends $16.10 on 4 beads and 5 marbles.
A bead costs $2.90 more than 1 marble.
- How much does 1 bead cost?
- How much do 7 beads cost?
- How much do a marble and 7 beads cost?
- How much do 7 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 4 beads and 5 marbles
= 4(1 u + 2.90) + 5 u
= 4 u + 11.60 + 5 u
= 4 u + 5 u + 11.60
= 9 u + 11.60
9 u + 11.60 = 16.10
9 u = 16.10 - 11.60
9 u = 4.50
1 u = 4.50 ÷ 9 = 0.50
Cost of 1 bead
= 1 u + 2.90
= 0.50 + 2.90
= $3.40
(b)
Cost of 7 beads
= 7 x 3.40
= $23.80
(c)
Cost of 1 marble and 7 beads
= 0.50 + 23.80
= $24.30
(d)
Cost of 7 beads more than 1 marble
= 23.80 - 0.50
= $23.30
Answer(s): (a) $3.40; (b) $23.80; (c) $24.30; (d) $23.30
