Adam pays $42 for 6 beads and 3 marbles.
5 beads cost as much as 1 marble.
- How much is 1 bead?
- How much is 1 marble?
- How much is 2 marbles and 5 beads?
(a)
Choose the smaller group to be 1 u.
Cost of 1 bead = 1 u
Cost of 5 beads = 5 u
Cost of 1 marble = 5 u
Cost of 6 beads
= 6 x 1 u
= 6 u
Cost of 3 marbles
= 3 x 5 u
= 15 u
Total cost of 6 beads and 3 marbles
= 6 u + 15 u
= 21 u
21 u = 42
1 u = 42 ÷ 21 = 2
Cost of 1 bead
= 1 u
= $2
(b)
Cost of 1 marble
= 5 u
= 5 x 2
= $10
(c)
Cost of 2 marbles and 5 beads
= 2 x 5 u + 5 x 1 u
= 10 u + 5 u
= 15 u
= 15 x 2
= $30
Answer(s): (a) $2; (b) $10; (c) $30