New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    A dice is rolled six times. What is the probability that

    a six appears on the sixth roll for the second time in 6 rolls?
    A 1/15 Correct Answer Incorrect Answer
    B 5/36 Correct Answer Incorrect Answer
    C 1/12 Correct Answer Incorrect Answer
    D 1/9 Correct Answer Incorrect Answer
    E 7/36 Correct Answer Incorrect Answer

    Solution

    Six can appear in these ways:
    6XXXX6, X6XXX6, XX6XX6, XXX6X6 and XXXX66
    Probability that a six appears on the sixth roll for the second time in 6 rolls
    = (1/6)*(1/6) + (1/6)*(1/6) + (1/6)*(1/6) + (1/6)*(1/6) + (1/6)*(1/6) = 5/36

    Practice Next

    Relevant for Exams: