320% is equal to 3 whole parts and 20% of a part. If one part is 100, then the mixed number would be 3 20/100. However, the problem says to simplify this, so it would be, 3 1/5!
Turn 320% into a decimal. You know that 300 means 3 whole, and 20 percent means fifths. So, first you would have 3 1/5. Turn 3 1/5 into simplest form and that's it!