SOLUTION: In a multiple choice exam, there are 5 questions and 4 choices for each question (a, b, c, d). Nancy has not studied for the exam at all and decides to randomly guess the answers.

Algebra ->  Probability-and-statistics -> SOLUTION: In a multiple choice exam, there are 5 questions and 4 choices for each question (a, b, c, d). Nancy has not studied for the exam at all and decides to randomly guess the answers.       Log On


   

Question 1185258: In a multiple choice exam, there are 5 questions and 4 choices for each question (a, b, c, d). Nancy has not studied for the exam at all and decides to randomly guess the answers. (Round your answers to four decimal places.)
What is the probability that the first question she gets right is the 2nd question?
Answer by ikleyn(52780) About Me  (Show Source):
You can put this solution on YOUR website!
.

Reformulated, the problem's question is 

    What is the probability that her answer for the first question is wrong,
    while the answer to the second question is correct ?


The probability that the answer to the first question is wrong is   3%2F4.

The probability that the answer to the second question is correct is   1%2F4.

THEREFORE,   the final probability under the problem's question is   P = %283%2F4%29%2A%281%2F4%29 = 3%2F16.             ANSWER

Solved.

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Notice that in this problem,  the total number of multiply choice questions  (5,  as given)  does not matter,

as well as what kind the questions are after the second question.


Only the nature of the first two questions does matter.