<human>:  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?
<bot>: How long did Carol spend writing the song? ** First find how long Carol spent writing the song in minutes: 4 hours * 60 minutes/hour = <<4*60=240>>240 minutes
How long did Carol spend recording the song? ** Then find how long she spent recording the song: 240 minutes / 2 = <<240/2=120>>120 minutes
How long did Carol spend in total? ** 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
How much time did Carol spend editing? ** 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%
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