To find the probability of multiple events, you must multiply the chance of one happening by the other. Since each question has 4 choices, and only one of them is right, the probability of you answering that question correctly is 1/4 The second question you answer correctly is has 1/4 probability as well. The third question you answer correctly has 1/4 probability. The fourth question (the one you get wrong) has a 3/4 chance of occurring because only 1 of the choices can be right and the other 3 are wrong. The fifth question (also the one you get wrong) has a 3/4 chance of occurring as well. So, now you have to multiple the probabilities of each question in order to find the probability of the quiz. 1/4 x 1/4 x 1/4 x 3/4 x 3/4= 0.008789063. The probability of getting 3 answers correct out of 5 is about 0.088%