Adam pays $31 for 5 marbles and 2 beads.
3 marbles cost as much as 5 beads.
- How much is 1 marble?
- How much is 1 bead?
- How much is 3 beads and 4 marbles?
(a)
LCM of 3 and 5 = 15
Cost of 3 marbles = 15 u
Cost of 1 marble = 15 u ÷ 3 = 5 u
Cost of 5 beads = 15 u
Cost of 1 bead = 15 u ÷ 5 = 3 u
Cost of 5 marbles = 5 x 5 u = 25 u
Cost of 2 beads = 2 x 3 u = 6 u
Total cost of 5 marbles and 2 beads
= 25 u + 6 u
= 31 u
31 u = 31
1 u = 31 ÷ 31 = 1
Cost of 1 marble
= 5 u
= 5 x 1
= $5
(b)
Cost of 1 bead
= 3 u
= 3 x 1
= $3
(c)
Cost of 3 beads and 4 marbles
= 3 x 3 u + 4 x 5 u
= 9 u + 20 u
= 29 u
= 29 x 1
= $29
Answer(s): (a) $5; (b) $3; (c) $29