Adam spends $12.10 on 2 marbles and 3 beads.
A marble costs 4 times as much as 1 bead.
- How much does 1 marble cost?
- How much do 3 marbles cost?
- How much do a bead and 3 marbles cost?
- How much does 1 bead cost less than 3 marbles?
(a)
Let the cheaper item be 1 u.
Cost of 1 bead = 1 u
Cost of 1 marble = 4 u
Cost of 2 marbles = 2 x 4 u = 8 u
Cost of 3 beads = 3 x 1 u = 3 u
Total cost of 2 marbles and 3 beads
= 8 u + 3 u
= 11 u
11 u = 12.10
1 u = 12.10 ÷ 11 = 1.10
Cost of 1 marble
= 4 u
= 4 x 1.10
= $4.40
(b)
Cost of 3 marbles
= 3 x 4.40
= $13.20
(c)
Cost of 1 bead and 3 marbles
= 1.10 + 13.20
= $14.30
(d)
Cost of 1 bead less than 3 marbles
= 13.20 - 1.10
= $12.10
Answer(s): (a) $4.40; (b) $13.20; (c) $14.30; (d) $12.10