Best to convert mixed numbers into fractions as mixed numbers are never helpful :P
1 5/6 is the same as 6/6 + 5/6 = 11/6
Now we just need to divide 11/6 by 2, which is the same as saying 11/6 multiplied by 1/2, so we double the denominator, therefore:
1 5/6 (11/6) divided by 2 is 11/12.