Adam spends $16.40 on 4 beads and 5 marbles.
A bead costs $1.40 more than 1 marble.
- How much does 1 bead cost?
- How much do 6 beads cost?
- How much do a marble and 6 beads cost?
- How much do 6 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 + 1.40
Total cost of 4 beads and 5 marbles
= 4(1 u + 1.40) + 5 u
= 4 u + 5.60 + 5 u
= 4 u + 5 u + 5.60
= 9 u + 5.60
9 u + 5.60 = 16.40
9 u = 16.40 - 5.60
9 u = 10.80
1 u = 10.80 ÷ 9 = 1.20
Cost of 1 bead
= 1 u + 1.40
= 1.20 + 1.40
= $2.60
(b)
Cost of 6 beads
= 6 x 2.60
= $15.60
(c)
Cost of 1 marble and 6 beads
= 1.20 + 15.60
= $16.80
(d)
Cost of 6 beads more than 1 marble
= 15.60 - 1.20
= $14.40
Answer(s): (a) $2.60; (b) $15.60; (c) $16.80; (d) $14.40