Adam spends $16.10 on 2 beads and 3 marbles.
A bead costs 2 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 = 2 u
Cost of 2 beads = 2 x 2 u = 4 u
Cost of 3 marbles = 3 x 1 u = 3 u
Total cost of 2 beads and 3 marbles
= 4 u + 3 u
= 7 u
7 u = 16.10
1 u = 16.10 ÷ 7 = 2.30
Cost of 1 bead
= 2 u
= 2 x 2.30
= $4.60
(b)
Cost of 3 beads
= 3 x 4.60
= $13.80
(c)
Cost of 1 marble and 3 beads
= 2.30 + 13.80
= $16.10
(d)
Cost of 1 marble less than 3 beads
= 13.80 - 2.30
= $11.50
Answer(s): (a) $4.60; (b) $13.80; (c) $16.10; (d) $11.50