Adam pays $30 for 2 marbles and 4 beads.
2 marbles cost as much as 1 bead.
- How much is 1 marble?
- How much is 1 bead?
- How much is 4 beads and 3 marbles?
(a)
Choose the smaller group to be 1 u.
Cost of 1 marble = 1 u
Cost of 2 marbles = 2 u
Cost of 1 bead = 2 u
Cost of 2 marbles
= 2 x 1 u
= 2 u
Cost of 4 beads
= 4 x 2 u
= 8 u
Total cost of 2 marbles and 4 beads
= 2 u + 8 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 4 beads and 3 marbles
= 4 x 2 u + 3 x 1 u
= 8 u + 3 u
= 11 u
= 11 x 3
= $33
Answer(s): (a) $3; (b) $6; (c) $33
