The simple answer: Don't.
The more detailed answer: Each SE has a specific set of FAQ and guidelines that specify what kind of questions may be appropriate there, and yes, there's a lot of overlap between the different SE sites. Your example is likely a usage issue of Apache on Ubuntu, so my gut feeling tells me that asking the question on Ask Ubuntu would be better than spreading it out everywhere.
This also encourages you to have a narrow scope with your question. This improves the quality and usefulness of the question, and has an effect on the answers, too.