Adam spends $13.20 on 2 beads and 3 marbles.
A bead costs 4 times as much as 1 marble.
- How much does 1 bead cost?
- How much do 3 beads cost?
- How much do a marble and 3 beads cost?
- How much does 1 marble cost less than 3 beads?
(a)
Let the cheaper item be 1 u.
Cost of 1 marble = 1 u
Cost of 1 bead = 4 u
Cost of 2 beads = 2 x 4 u = 8 u
Cost of 3 marbles = 3 x 1 u = 3 u
Total cost of 2 beads and 3 marbles
= 8 u + 3 u
= 11 u
11 u = 13.20
1 u = 13.20 ÷ 11 = 1.20
Cost of 1 bead
= 4 u
= 4 x 1.20
= $4.80
(b)
Cost of 3 beads
= 3 x 4.80
= $14.40
(c)
Cost of 1 marble and 3 beads
= 1.20 + 14.40
= $15.60
(d)
Cost of 1 marble less than 3 beads
= 14.40 - 1.20
= $13.20
Answer(s): (a) $4.80; (b) $14.40; (c) $15.60; (d) $13.20