How Many Questions Did You Practice on GMAT Club?

I wanted to practice stamina and be able to stay concentrated for a long time, so I would try to do maybe 20 questions in a row. And then I'd go back and analyze them one by one to see what I did wrong or maybe what I did really good. So I was using the question bank on GMAT club and I would mostly use the Manhattan questions and Veritas and the economists because those were the ones that I found most similar to the official questions. Sometimes if I wanted some really hard, quite questions, I would go for a GMAT because they had some pretty hard ones.