Another tip: if you finish early and are reviewing your answers, never change one unless you are SURE it’s wrong. Maybe it’s just me, but if I’m at all unsure, my initial gut feel the first time turns out correct a lot more than when I go back and over-think it.
Guess anyway. I have never heard of a test where the penalty was enough to make the expected value of guessing negative. At worst it offsets your odds of randomly getting the correct answer to make the expected value zero… same as if you left it blank. They would like you to believe that you shouldn’t guess, but that’s not what the math says.
And if you can eliminate one (or more) of the choices as clearly wrong, your expected value is positive for guessing.