There are several information’s
of immense importance already given in the question. Based on those information’s
the answer can be easily deduced.
Amount of vinegar required for making 1 recipe of salad dressing = 1/4 cup
Amount of vinegar available = 4 cups
Then
The number of salad dressings that could be made = [1/(1/4)] * 4
= 4 * 4
= 16
So 16 salad dressings could be made with the amount of vinegar available. I hope the procedure is clear enough for you to understand.