Not sure about the rules, but whatever they say, I wouldn't recommend doing this. There isn't much to gain, and there are two significant drawbacks:
- The question history will be clobbered with an unrelated question.
- The date of the question will not be correct (and users trying to help may not understand immediately why it's so).
Additionally, the deleted question gets some visibility. Normally, a deleted question is only visible by you, and people who have both enough reputation (10k) and the link to the question (impossible to find it otherwise, except maybe for moderators) - usually that's very few people.
If it's deleted, so be it. If you have another question, ask another question.
By the way, when you get to 10k rep, you can see your own deleted posts by searching deleted:1
For an answer, however, I think reusing a deleted answer does not harm much, if there were no votes. You may also decide to provide another answer and leave the deleted one: there may be reasons, such as keeping another approach for future correction. Then I'd recommend replacing the contents of the deleted one with a single line (30 dots for instance), so as to reduce the occupied space in the list - because it's visible even if it's deleted, once you get to 10k rep.