New RBI Grade B 2025 Notification will come Soon! Enroll Here

    Question

    A bag contains 5 red books, 7 yellowbooks

    and 7 greenbooks . 3books are drawn randomly. What is the probability that thebooks drawn is not a green book ?
    A 17/759 Correct Answer Incorrect Answer
    B 100/969 Correct Answer Incorrect Answer
    C 220/969 Correct Answer Incorrect Answer
    D 307/969 Correct Answer Incorrect Answer
    E none of these Correct Answer Incorrect Answer

    Solution

    Total number of books = 5 + 7 + 7 = 19 Let S be the sample space. Then, n(S) = number of ways of drawing 3 books out of 19 = 19C3 = `(19 xx 18 xx 17)/ (3 xx 2 xx 1)` = 969 Let E= event of drawing no green books n(E) = 12C3 = `(12 xx 11 xx 10)/(3 xx 2 xx 1)` = 220 `:.` P(E) = `(n(E))/(n(S))` = `220/969`

    Practice Next