At a shop, Shiyun paid $21 for 1 marble and 3 beads. The marble cost $9 more than each bead.
- How much is 1 bead?
- How much is 1 marble?
(a)
Cost of 1 bead = 1 u
Cost of 3 beads = 3 u
Cost of 1 marble = 1 u + 9
Total cost of 1 marble and 3 beads
= 3 u + 1 u + 9
= 4 u + 9
4 u + 9 = 21
4 u = 21 - 9
4 u = 12
1 u = 12 ÷ 4 = 3
Cost of 1 bead
= 1 u
= $3
(b)
Cost of 1 marble
= 1 u + 9
= 3 + 9
= $12
Answer(s): (a) $3; (b) $12