Adam spends $13.30 on 2 beads and 3 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 2 beads and 3 marbles
= 2(1 u + 2.90) + 3 u
= 2 u + 5.80 + 3 u
= 2 u + 3 u + 5.80
= 5 u + 5.80
5 u + 5.80 = 13.30
5 u = 13.30 - 5.80
5 u = 7.50
1 u = 7.50 ÷ 5 = 1.50
Cost of 1 bead
= 1 u + 2.90
= 1.50 + 2.90
= $4.40
(b)
Cost of 7 beads
= 7 x 4.40
= $30.80
(c)
Cost of 1 marble and 7 beads
= 1.50 + 30.80
= $32.30
(d)
Cost of 7 beads more than 1 marble
= 30.80 - 1.50
= $29.30
Answer(s): (a) $4.40; (b) $30.80; (c) $32.30; (d) $29.30