No problem, The sample tests in C# seem fine, and there is a fixed test for n = 10 in the final tests:

Assert.AreEqual("Great, now move on to tricks", Kata.HoopCount(10), "Should work for 10");

That also looks good.

Yes, It passes the test if n = 10. What I want to say is test sample does not seem do be correct. Sorry if I talk big. I just starded to learn coding.

And that's what you're asked to do:

If Alex gets 10 or more hoops, return the string "Great, now move on to tricks".

This code returns "Great, now move on to tricks" if n = 10
So this is not the best practice. We should instead ask if n >= 10.

My bad, I do realize I'm truncating and not actually rounding