At Ask.com, we believe questions are forever! We only remove items that violate our Community Guidelines; otherwise, they are here to stay. This benefits not only people in Ask.com reading along right now, but down the road when other people search the web for the same information, your contributions today can help these other people down the road for a long time to come! Therefore, choose your words accordingly. :-)
If you have a specific need for removal of a question or answer, though, we'd like to hear about it. Please get in touch with our Customer Support team to patiently explain the circumstances.
You can't yourself, however Mods can if it is reported and they find it violates a community guideline or something. Also, if it's been less than 15 minutes since it was asked, you can edit it and put something unacceptable in the title (like a profanity) and it should go down immediately. That's probably not the best advice, but that's what you get for reading what some random put on the Internet.