Adam spends $16.90 on 2 beads and 3 marbles.
A bead costs $1.20 more than 1 marble.
- How much does 1 bead cost?
- How much do 8 beads cost?
- How much do a marble and 8 beads cost?
- How much do 8 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 + 1.20
Total cost of 2 beads and 3 marbles
= 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 = 16.90
5 u = 16.90 - 2.40
5 u = 14.50
1 u = 14.50 ÷ 5 = 2.90
Cost of 1 bead
= 1 u + 1.20
= 2.90 + 1.20
= $4.10
(b)
Cost of 8 beads
= 8 x 4.10
= $32.80
(c)
Cost of 1 marble and 8 beads
= 2.90 + 32.80
= $35.70
(d)
Cost of 8 beads more than 1 marble
= 32.80 - 2.90
= $29.90
Answer(s): (a) $4.10; (b) $32.80; (c) $35.70; (d) $29.90