Adam spends $16.90 on 4 beads and 5 marbles.
A bead costs $1.30 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 + 1.30
Total cost of 4 beads and 5 marbles
= 4(1 u + 1.30) + 5 u
= 4 u + 5.20 + 5 u
= 4 u + 5 u + 5.20
= 9 u + 5.20
9 u + 5.20 = 16.90
9 u = 16.90 - 5.20
9 u = 11.70
1 u = 11.70 ÷ 9 = 1.30
Cost of 1 bead
= 1 u + 1.30
= 1.30 + 1.30
= $2.60
(b)
Cost of 8 beads
= 8 x 2.60
= $20.80
(c)
Cost of 1 marble and 8 beads
= 1.30 + 20.80
= $22.10
(d)
Cost of 8 beads more than 1 marble
= 20.80 - 1.30
= $19.50
Answer(s): (a) $2.60; (b) $20.80; (c) $22.10; (d) $19.50