A wedding planner uses 72 ivy stems for 18 centerpieces. When she arrives at the venue, she realizes she will only need 16 centerpieces. How many ivy stem should she use so that the ratio of ivy stems to centerpieces stays the same?

64 ivy stems

Step-by-step explanation:

A wedding planner uses 72 ivy stems for 18 centerpieces.

for only need 16 centerpieces ⇒ she will use x ivy stems

Using the ratio and the proportional

ivy stems : centerpieces

72 : 18

x : 16

Solve for x

∴ x = 16 * 72/18 = 64 ivy stems

So, she should us 64 ivy stems