Adam spends $16.10 on 4 beads and 5 marbles.
A bead costs $1.10 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 + 1.10
Total cost of 4 beads and 5 marbles
= 4(1 u + 1.10) + 5 u
= 4 u + 4.40 + 5 u
= 4 u + 5 u + 4.40
= 9 u + 4.40
9 u + 4.40 = 16.10
9 u = 16.10 - 4.40
9 u = 11.70
1 u = 11.70 ÷ 9 = 1.30
Cost of 1 bead
= 1 u + 1.10
= 1.30 + 1.10
= $2.40
(b)
Cost of 7 beads
= 7 x 2.40
= $16.80
(c)
Cost of 1 marble and 7 beads
= 1.30 + 16.80
= $18.10
(d)
Cost of 7 beads more than 1 marble
= 16.80 - 1.30
= $15.50
Answer(s): (a) $2.40; (b) $16.80; (c) $18.10; (d) $15.50