how do you edit a question you have asked on yahoo answers?

You can't exactly edit your question, you can only add details to it. You can do that by hovering your mouse over the pencil icon and clicking Add Details. Say what you want (but don't chat), then submit.

If you make spelling errors and such, then that's too bad. You could only add details and correct it there.

You can add details, but you can not edit. That is to prevent askers from doing this.

Asking "Do you think Obama is the devil?"

Getting 25 answers, then editing to

"Do you think Bush is the devil?"

You can see the problem it causes. They let you edit the answers, because that only impacts that one answer, not all of them.

You can't edit it you can only have an added statement. below the question.