25 over 30= x over 100. OR SIMPLIFIED: 5 over 6= x over 100. 1. 100 x 5= 500 2. 500 divided by 6= 83.333333... 3. 83.3 or 83.33 depending on how you round. THE PERCENTAGE IS 83.3 WITH A REPEATING BAR OVER THE 3 AFTER THE DECIMAL POINT. I hope I answered your question ;-)