5/11
28/55 is in its simplest form.
38/55 is in its simplest form.
55/64 is in its simplest form.
54/55 is in its simplest form.
36/55 is in its simplest form.
55/7 is in its simplest form.
56/55 is already in its simplest form
55/12 is already in its simplest form
Common factor is 5 so 5/11
9/55 is already in simplest form!
It is already in its simplest form as 55/36