Adam pays $20 for 2 marbles and 4 beads.
4 marbles cost as much as 2 beads.
- How much is 1 marble?
- How much is 1 bead?
- How much is 3 beads and 4 marbles?
(a)
LCM of 4 and 2 = 4
Cost of 4 marbles = 4 u
Cost of 1 marble = 4 u ÷ 4 = 1 u
Cost of 2 beads = 4 u
Cost of 1 bead = 4 u ÷ 2 = 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 = 20
1 u = 20 ÷ 10 = 2
Cost of 1 marble
= 1 u
= 1 x 2
= $2
(b)
Cost of 1 bead
= 2 u
= 2 x 2
= $4
(c)
Cost of 3 beads and 4 marbles
= 3 x 2 u + 4 x 1 u
= 6 u + 4 u
= 10 u
= 10 x 2
= $20
Answer(s): (a) $2; (b) $4; (c) $20