There is no direct answer to that.. Depends how the stars are aligned, especially if you work with biologics! Something that may take a couple of hours normally could leave you pulling your hair out for weeks.. Or you may get incredibly lucky and hit on something first go. There are no rules or sense in research when it comes to how long an experiment should take!
For my experiments if all goes well, I can get an experiment done in about 6 hours. Sometimes the experiments take a bit of optimising to get the best results but with a bit of tweeking I can usually get an answer within a week or two depending on what I’m doing!
That really depends on the experiment! If something interesting happens, I usually have to run have to the experiment multiple times to ensure the data is consistent and not just a fluke. For very big projects it could take weeks to co-ordinate with everyone involved to get everything tied up!