Just to elaborate on my previous answer. You should first multiply the denominator by something to get it to one hundred. Whatever you do to the denominator, you have to do to the numerator.
11/50 * 2/2 = 22/100
The numerator that is placed over 100 is that percentage. In this case, it is 22%
11/50 * 2/2 = 22/100
The numerator that is placed over 100 is that percentage. In this case, it is 22%