CHANCES: 

That the return portion of the bill will tear off at the perforation – 17%

That there isn’t a worthwhile perforation and you just rip jagged edges trying to get it off – 26%

That the bill will be folded just below the perforation and tear there instead, so it is just a ¼ inch too big to fit in the envelope and you’ve got to spend 15 minutes looking for a pair of scissors to cut that little portion off, but when you can’t find them you try manually ripping it and get so frustrated that you just don’t pay your bill and the next month you wonder why you have all these extra fees for non-payment and you spend an hour on the phone with them trying to get the fees removed by arguing that it’s their fault because they can’t fold a damn bill where it’s supposed to be folded – 57%