10/33
66/20 = 33/10 = 3 and 3/10
66/40 = 33/20
If you mean 20/66 then it is 10/33 in its simplest form
It is already in its simplest form.
6620 is an integer and there is no sensible representation as a mixed number.
11/20
It is: 46/66 = 23/33
It is: 88/66 = 4/3
11/66 = 1/6
46/66 = 23/33
18/66 = 3/11