Adam pays $42 for 3 marbles and 2 beads.
8 marbles cost as much as 4 beads.
- How much is 1 marble?
- How much is 1 bead?
- How much is 4 beads and 2 marbles?
(a)
Choose the smaller group to be 1 u.
Cost of 8 marbles = Cost of 4 beads
Cost of 2 marbles = Cost of 1 bead
Cost of 1 marble = 1 u
Cost of 1 bead = 2 u
Cost of 3 marbles
= 3 x 1 u
= 3 u
Cost of 2 beads
= 2 x 2 u
= 4 u
Total cost of 3 marbles and 2 beads
= 3 u + 4 u
= 7 u
7 u = 42
1 u = 42 ÷ 7 = 6
Cost of 1 marble = 1 u = $6
(b)
Cost of 1 bead
= 2 u
= 2 x 6
= $12
(c)
Cost of 4 beads and 2 marbles
= 4 x 2 u + 2 x 1 u
= 8 u + 2 u
= 10 u
= 10 x 6
= $60
Answer(s): (a) $6; (b) $12; (c) $60
