Adam spends $15.90 on 3 beads and 4 marbles.
A bead costs $1.10 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 + 1.10
Total cost of 3 beads and 4 marbles
= 3(1 u + 1.10) + 4 u
= 3 u + 3.30 + 4 u
= 3 u + 4 u + 3.30
= 7 u + 3.30
7 u + 3.30 = 15.90
7 u = 15.90 - 3.30
7 u = 12.60
1 u = 12.60 ÷ 7 = 1.80
Cost of 1 bead
= 1 u + 1.10
= 1.80 + 1.10
= $2.90
(b)
Cost of 6 beads
= 6 x 2.90
= $17.40
(c)
Cost of 1 marble and 6 beads
= 1.80 + 17.40
= $19.20
(d)
Cost of 6 beads more than 1 marble
= 17.40 - 1.80
= $15.60
Answer(s): (a) $2.90; (b) $17.40; (c) $19.20; (d) $15.60
