About sets of 37... well, I don't think it's a good idea. Questions are arranged from easy to hard.
I was so eager to run the first 150 questions or so, thinking it was so easy. I first thought GMAT math was yummy. Unfortunately I wasn't right.
My speed reduced significantly when I hit the latter questions.
However the last 200 questions do contain some pretty easy ones, so that you wouldn't be discouraged, perhaps.
And you'll see yourself out of concentration sometimes, you solve the easy ones using significant amount of time. That happened to me.