Adam pays $38 for 3 marbles and 4 beads.
4 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 4 marbles = 4 u
Cost of 1 bead = 4 u
Cost of 3 marbles
= 3 x 1 u
= 3 u
Cost of 4 beads
= 4 x 4 u
= 16 u
Total cost of 3 marbles and 4 beads
= 3 u + 16 u
= 19 u
19 u = 38
1 u = 38 ÷ 19 = 2
Cost of 1 marble
= 1 u
= $2
(b)
Cost of 1 bead
= 4 u
= 4 x 2
= $8
(c)
Cost of 4 beads and 3 marbles
= 4 x 4 u + 3 x 1 u
= 16 u + 3 u
= 19 u
= 19 x 2
= $38
Answer(s): (a) $2; (b) $8; (c) $38