CEE Kerala Engineering CEE Kerala Engineering Solved Paper-2009

  • question_answer
    The mean of the values 0, 1, 2, 3, ..., n with the corresponding   weights\[^{n}{{C}_{0}}{{,}^{n}}{{C}_{1}},....{{,}^{n}}{{C}_{n}}\]respectively, is

    A)  \[\frac{n+1}{2}\]                            

    B)  \[\frac{n-1}{2}\]

    C)  \[\frac{{{2}^{n}}-1}{2}\]              

    D)         \[\frac{{{2}^{n}}+1}{2}\]

    E)  \[\frac{n}{2}\]

    Correct Answer: E

    Solution :

    Mean \[=\frac{0{{\times }^{n}}{{C}_{0}}+1{{\times }^{n}}{{C}_{1}}+2{{\times }^{n}}{{C}_{2}}+...+n{{\times }^{n}}{{C}_{n}}}{^{n}{{C}_{0}}{{+}^{n}}{{C}_{1}}{{+}^{n}}{{C}_{2}}+...{{+}^{n}}{{C}_{n}}}\] \[=\frac{0+1{{\times }^{n}}{{C}_{1}}+2{{\times }^{n}}{{C}_{2}}+...+n{{\times }^{n}}{{C}_{n}}}{{{2}^{n}}}\]                 \[=\frac{n{{.2}^{n-1}}}{{{2}^{n}}}=\frac{n}{2}\]


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