Rachel spends 1 + 1 = <<1+1=2>>2 hours setting up and cleaning up.
She paints for 1 hour x 4 paintings = <<1*4=4>>4 hours.
Then she edits 1.5 hours x 4 videos = <<1.5*4=6>>6 hours.
She spends 2 + 4 + 6 = <<2+4+6=12>>12 hours to make 4 videos.
So Rachel spends 12 / 4 = <<12/4=3>>3 hours on each video.
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