A dozen eggs = 12 eggs.
Albert had 1/3 eggs, which 12 / 3 = 4, so he had 4 eggs.
Maria had 1/4 eggs, which 12 / 4 = 3, so she had 3 eggs.
Tom had 2/6 eggs, which converts to 1/3 and once again results into 4, so he had 4 eggs.
Let's add these up and subtract our sum from our total.
4 + 3 = 7
7 + 4 = 11
12 - 11 = 1
We have 1/12 eggs left.
I hope this helps!