If you're talking about a specific project, use "How long will it take you to finish the report?" But if you're talking about reports in general, you can say, "How long does it take you to finish a report?"

I prefer 2 - how long will it take you - so long as the report is not finished yet. If the report is one of many, you might say "How long does it take you to finish a report?" That way you are asking for the typical time taken.

Both can be correct as Alysha says. The difference between the two questions is as follows: 1 - can be a general type question. For example, when you write a report (any report) in general how long does it take you to finish it? 2 - specifically for the report you are working on, when will you finish it? I hope that helps.

Both is right it depends on witch time you need to use