The part is 9 and the whole is 25. You need to find the percent.

Let n represent the percent.

Part = percentwhole

              (Substitute part = 9 and whole = 25)

       (Divide each side by 25)

                (Cancel common terms)

               (Divide: )

  (Multiply with 100 and add percent sign)

                (Multiply: )

9 is 36 of 25.