CEE Kerala Engineering CEE Kerala Engineering Solved Paper-2004

  • question_answer
    A and B toss a coin alternately till one of them tosses heads and wins the game, their respective probabilities of winning are;

    A)  \[\frac{1}{4}and\frac{3}{4}\]

    B)  \[\frac{1}{2}and\frac{1}{2}\]

    C)  \[\frac{2}{3}and\frac{1}{3}\]

    D)  \[\frac{1}{5}and\frac{4}{5}\]

    E)  0 and 1

    Correct Answer: C

    Solution :

    The probability of winning A \[=\frac{1}{2}+\frac{1}{2}\times \frac{1}{2}\times \frac{1}{2}+....\] \[=\frac{1}{2}+{{\left( \frac{1}{2} \right)}^{3}}+{{\left( \frac{1}{2} \right)}^{5}}+....\] \[=\frac{1}{2}\left[ \frac{1}{1-\frac{1}{4}} \right]=\frac{2}{3}\] The probability of winning B \[=\frac{1}{2}\times \frac{1}{2}+\frac{1}{2}\times \frac{1}{2}\times \frac{1}{2}\times \frac{1}{2}+.....\]                 \[={{\left( \frac{1}{2} \right)}^{2}}+{{\left( \frac{1}{2} \right)}^{4}}+.....\]                 \[=\frac{1}{4}\left[ \frac{1}{1-\frac{1}{4}} \right]=\frac{1}{3}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner