Adam pays $42 for 2 marbles and 4 beads.
3 marbles cost as much as 1 bead.
- How much is 1 marble?
- How much is 1 bead?
- How much is 5 beads and 3 marbles?
(a)
Choose the smaller group to be 1 u.
Cost of 1 marble = 1 u
Cost of 3 marbles = 3 u
Cost of 1 bead = 3 u
Cost of 2 marbles
= 2 x 1 u
= 2 u
Cost of 4 beads
= 4 x 3 u
= 12 u
Total cost of 2 marbles and 4 beads
= 2 u + 12 u
= 14 u
14 u = 42
1 u = 42 ÷ 14 = 3
Cost of 1 marble
= 1 u
= $3
(b)
Cost of 1 bead
= 3 u
= 3 x 3
= $9
(c)
Cost of 5 beads and 3 marbles
= 5 x 3 u + 3 x 1 u
= 15 u + 3 u
= 18 u
= 18 x 3
= $54
Answer(s): (a) $3; (b) $9; (c) $54