Carol spends 4 hours writing a song, half that much time recording it, and 90 minutes editing it. What percentage of her total work time did she spend editing?
First find how long Carol spent writing the song in minutes: 4 hours * 60 minutes/hour = <<4*60=240>>240 minutes
Then find how long she spent recording the song: 240 minutes / 2 = <<240/2=120>>120 minutes
Then add up all her work time to find the total work time: 240 minutes + 120 minutes + 90 minutes = <<240+120+90=450>>450 ​minutes
Then divide her editing time by her total work time and multiply by 100% to express the answer as a percentage: 90 minutes / 450 minutes * 100% = 20%
#### 20