Adam pays $30 for 4 marbles and 3 beads.
4 marbles cost as much as 2 beads.
- How much is 1 marble?
- How much is 1 bead?
- How much is 5 beads and 2 marbles?
(a)
Choose the smaller group to be 1 u.
Cost of 4 marbles = Cost of 2 beads
Cost of 2 marbles = Cost of 1 bead
Cost of 1 marble = 1 u
Cost of 1 bead = 2 u
Cost of 4 marbles
= 4 x 1 u
= 4 u
Cost of 3 beads
= 3 x 2 u
= 6 u
Total cost of 4 marbles and 3 beads
= 4 u + 6 u
= 10 u
10 u = 30
1 u = 30 ÷ 10 = 3
Cost of 1 marble = 1 u = $3
(b)
Cost of 1 bead
= 2 u
= 2 x 3
= $6
(c)
Cost of 5 beads and 2 marbles
= 5 x 2 u + 2 x 1 u
= 10 u + 2 u
= 12 u
= 12 x 3
= $36
Answer(s): (a) $3; (b) $6; (c) $36
