How to guess on CFA exam and apply Monty Hall (kind of)


So, let’s say you solved 110 problems and did not know answer to rest of 10 questions.

Before going back to questions, pick a letter (a, b or c) and this letter is going to be your first choice for all questions.

Then, read questions carefully and try to eliminate one with your best of knowledge.

If the answer you elminated was not the letter you picked originally, then switch your answer.

If you can’t eliminate an answer, or if the answer you eliminated was the letter you picked, I don’t know. up to you. do whatever you want…

you’re welcome for doubling your chances of guessing.

get me a job plz. thanks.

I’m following the same stratergy. Hope we don’t have to use it that often in the exam though.

I am picking option B for any guesses. I believe this is possibly better for numerical problems as anwers are arranged increasing order.

This doesn’t work unfortunately.

Imagine for example that you guess randomly initally, then you determine that answer C is wrong. Also, let’s say answer A happens to be the correct one.

1.) If you guessed A -> remove C -> Switch to B -> Wrong

2.) If you guessed B -> remove C -> Switch to A -> Correct

3.) If you guessed C -> remove C -> have to guess at 50%.

So you are still at 50%.

The difference to Monty Hall is that after your initial guess, the host removes with 100% certainty a wrong option that is NOT your initial guess. In option 3 whter you guessed C, he would have removed the wrong answer B, letting you switch to A and get it right.

Assuming your elimination is 100% correct, this SHOULD work.

If you’re considering this as an option you should be worried.


I’m only considering this for econ, my fail subject.

Wow. You must be so well prepared that you won’t have to guess a single question on the exam.

Someone explain this??? I’m just guessing, but I like your idea. kind of like how it makes sense to always change your door (when you have 3, on the second round).

So I should randomly pick B for all my guesses. Then read through the question and…

It’s not.

could you please explain =) ? seems like you know much more than most of us…

Because on montry hall we have no idea, for example, what is behind the door. Whereas during the exam we have more information and therefore is not entirely ‘luck’. I think… But then I guess elimintating one answer is similar to revealing one door. Confused…

In the Monty Hall problem, you have a 1/3 chance of guessing correctly, then Monty shows you one of the other doors (with a goat) and asks if you want to switch. Your initial guess still has a 1/3 chance of being correct, so switching gives you a 2/3 chance of winning. Which door Monty shows you depends on which door you select initially, so _ your initial guess matters _.

On the Level I CFA exam, _ your initial guess doesn’t matter _; you’ll eliminate the same wrong answer no matter whether you chose A, B, or C on your initial guess. Once that answer’s gone, there are two left: if you guess, it’s 50/50.

(Actually, for me it’s more like 25/75: I’m a horrible guesser. That’s why I’d rather know than guess, and why I studied like mad before taking these tests.)

I love you <3

So does my horse. (When I give him a peppermint, that is.)

It doesn’t work. Because probabilities is a bunch of… err, well, (in my opinion) baloney. Which is why I have so much trouble with it cause I see probability of xx, I go: “so what?”

I didn’t mean it as an insult… I am sure I will have to intelligently guess the more correct answer here or there.