00:01
In this problem, it is said that there are four multiple choice questions on an exam, each with four possible answers.
00:06
You do not know the answers and are guessing, so what is the probability that you will answer at least one question out of four correctly? so let us consider c to be the event that you answer one question correctly.
00:19
Now, let us determine the probability of c.
00:21
This will be the number of favorable outcomes divided by the total number of outcomes.
00:25
Now, each question has four possible answers, only one is correct.
00:30
The probability of getting an answer is correct is 1 by 4, which is 0 .25.
00:34
From here, we can determine the probability of c complement, which is the probability that the answer is not correct.
00:40
Using the complement rule of probability, this is 1 minus p of c, so we have 1 minus 0 .25, that is equal to 0 .75.
00:49
Now, we have been asked to determine the probability that you get at least one question correct.
00:57
And using the complementary rule of probability, this is equal to one minus the probability of the complementary event...