A serving of filet mignon is generally considered to be about 1/4
lb. How many servings can be prepared from 7 1/3
lb of filets?

If 1 serving = 1/4 pound, then 4 servings = 1 pound. 6 pounds *4=24 servings. That leaves 1/3 of a pound. 1/4 pound is less than 1/3 pound, so you get one more serving.

That makes 25 servings, and 1/12 of a pound left over.

How do you know it is 1/12? Well, LCD (lowest common denominator) shows that 1/3-1/4= 4/12-3/12=1/12.