The clothes take 30 minutes to wash and the towels take twice as long, 30 x 2 = <<30*2=60>>60 minutes to wash the towels.
The sheets take 15 minutes less than the towels, 60 - 15 = <<60-15=45>>45 minutes to wash the sheets.
It takes 30 minutes + 60 minutes + 45 minutes = <<30+60+45=135>>135 minutes to wash everything.
#### 135