Here's the secret to a CLEP.
1) Find out how many answers you need to get right to pass. This is usually in the 40-46 range.
2) Start the test. Go through the test and answer every question you KNOW is right. Mark these off with an A by the question when you answer it.
2) Now go through the test and answer any questions that may have their answers in the question of another question:
for instance, you may find a question that says "In what year did Bob discover Fred?", then several questions later, the question is "When Bob discovered Fred in 1975, what was the result"...Get the point. You have to go through the test once to see if this happens.
3) Now count up how many questions you have answered RIGHT so far (at this point, you have many questions unanswered). If it is sufficiently greater than the required score, then stop - you are done.
Why?
Because you are DINGED 1/4 point for every wrong answer. The key to CLEPing is to NOT just answer all the questions, but only answer enough to pass, because wrong answers count AGAINST you.
4) If you have not answered a confortable amount above the required, then go through the test and find the ones you have the best chance of getting right - one's you can eliminate down to a 50/50 chance, and answer enough of those to get you decently past the required passing number.
Good luck!