Adam pays $18 for 3 marbles and 5 beads.
6 marbles cost as much as 2 beads.
- How much is 1 marble?
- How much is 1 bead?
- How much is 3 beads and 2 marbles?
(a)
Choose the smaller group to be 1 u.
Cost of 6 marbles = Cost of 2 beads
Cost of 3 marbles = Cost of 1 bead
Cost of 1 marble = 1 u
Cost of 1 bead = 3 u
Cost of 3 marbles
= 3 x 1 u
= 3 u
Cost of 5 beads
= 5 x 3 u
= 15 u
Total cost of 3 marbles and 5 beads
= 3 u + 15 u
= 18 u
18 u = 18
1 u = 18 ÷ 18 = 1
Cost of 1 marble = 1 u = $1
(b)
Cost of 1 bead
= 3 u
= 3 x 1
= $3
(c)
Cost of 3 beads and 2 marbles
= 3 x 3 u + 2 x 1 u
= 9 u + 2 u
= 11 u
= 11 x 1
= $11
Answer(s): (a) $1; (b) $3; (c) $11
