First you would change the time from minutes to seconds by multiplying 4 by 60 because there are 60 seconds in a minute. After finding that (4*60=240) you would subtract the remaining time (12 seconds) from the total time (240 seconds). You would subtract the remaining time from the total time (228 seconds). Using that you would use the ratio time used/total (228/240). Divide that out and multiply by 100 to get 95%. I hope that helps!