As a break from Level 2 study: Each Qn has 3 choices and there are a total of 120 Questions in CFA Level 2 exam. If a candidate can answer 70 % of Qns (84 correct answers out of 120 questions), he/she is deemed to be passed. What is the probability of a candidate passing if all questions are answered randomly.
Near zero. I have a better one for you. They give you a choice of two exam formats. format A): To pass you need to get all questions wrong. format B): The current CFA format. Which one would you take?
Hahahahhaha current format…it is impossible to get everything wrong…on a qestion you dont know youre gonna end up getting it right for sure ahha
I’ll take Format A. Leave everything blank and I’ll be wrong on all.
Wouldn’t it be the prob of choosing the 1 correct pattern out of 3^120 possible combinations? You have 3 possible answers for q1. Times 3 possible for the next one. Times 3 for q3. So, 1 in 27 after just 3 questions.
Aztek Wrote: ------------------------------------------------------- > As a break from Level 2 study: > > Each Qn has 3 choices and there are a total of 120 > Questions in CFA Level 2 exam. If a candidate can > answer 70 % of Qns (84 correct answers out of 120 > questions), he/she is deemed to be passed. What is > the probability of a candidate passing if all > questions are answered randomly. This probability is very low. When you answer all questions randomly, your expectation will be 1/3 x 120 = 40 right answers. The variance of a binomial distribution is np(1-p), which means that a (120,1/3) distribution has a variance of 120 x 1/3 x 2/3 = 26.7 and a standard deviation of 26.7^0.5=5.2. Since you need to get 84 questions right, you should be (84-40)/5.2=8.5 standard deviations above the mean. I guess the probability of passing this way is less than 1 in a million.
zoya Wrote: ------------------------------------------------------- > Wouldn’t it be the prob of choosing the 1 correct > pattern out of 3^120 possible combinations? You > have 3 possible answers for q1. Times 3 possible > for the next one. Times 3 for q3. So, 1 in 27 > after just 3 questions. There are 2 incorrect answers, so it will be (2/3)^n instead of (1/3)^n.