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  3. JEE Main & Advanced

JEE Main & Advanced Sample Paper JEE Main Sample Paper-20

  • question_answer
    Three people each flip two fair coins. The probability that exactly two of the people flipped one head and one tail, is-

    A) \[1/2\]                                 

    B) \[3/8\]

    C) \[5/8\]                                 

    D) \[3/4\]

    Correct Answer: B

    Solution :

    \[n=3,\,\,P\](success)\[=P(HT\,\,or\,\,TH)=1/2\] \[\Rightarrow \]\[p=q=\frac{1}{2}\]and\[r=2\]                 \[P(r=2){{=}^{3}}{{C}_{2}}{{\left( \frac{1}{2} \right)}^{2}}\cdot \frac{1}{2}=\frac{3}{8}\]


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