Before you express in the percentage, they must all be in the same unitsChange the hours to minutes1 hour =60 minutes3 hours =3×60 minutes =180 minutes3 hours 20 minutes =180 minutes +20 minutes =200 minutesPercentage = Number/Total ×10030 minutes of 3 hours 20 minutes ( 200 minutes) in percentage,20030×100=15100 goes into 200, 2 times and 2 goes into 30, 15 times