Answer:
24 times
Explanation:
Given : A small bottle of vanilla extract has 16 ounces in it.
To Find : if each batch of cookies baked requires 2/3 of an ounce of vanilla how many times can the bakery use the bottle before it is empty?
Solution : 
No. of batch of cookies requires 2/3 ounce of vanilla = 1
No, of batch of cookies requires 1 ounce of vanilla = 

No. of batches require 16 ounces of vanilla = 

 = 24
Thus, bakery can use 24 times the bottle before it is empty.