JEE Main & Advanced Mathematics Probability Question Bank Self Evaluation Test - Probability-I

  • question_answer
    A cricket club has 15 members, of whom only 5 can bowl. If the name of 15 members are put into a box and 11 are drawn at random, then the probability of getting an eleven contain at least 3 bowlers is

    A) 7/13     

    B) 6/13

    C) 11/15

    D) 12/13

    Correct Answer: D

    Solution :

    [d] The total number of ways of choosing 11 players out of 15 is \[^{15}{{C}_{11}}.\] A team of 11 players containing at least 3 bowlers can be chosen in the following mutually exclusive ways: (I) Three bowlers out of 5 bowlers and 8 other players out of the remaining 10 players. (II) Four bowlers out of 5 bowlers and 7 other Players out of the remaining 10 players. (III) Five bowlers out of 5 bowlers and 6 other players out of the remaining 10 players. So, required probability \[=P(I)+P(II)+P(III)\] \[=\frac{^{5}{{C}_{3}}{{\times }^{10}}{{C}_{8}}}{^{15}{{C}_{11}}}+\frac{^{5}{{C}_{4}}{{\times }^{10}}{{C}_{7}}}{^{15}{{C}_{11}}}+\frac{^{5}{{C}_{5}}{{\times }^{10}}{{C}_{6}}}{^{15}{{C}_{11}}}=\frac{12}{13}.\]


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