JEE Main & Advanced JEE Main Solved Paper-2016

  • question_answer
    \[\underset{n\to \infty }{\mathop{\lim }}\,{{\left( \frac{(n+1)(n+2)....3n}{{{n}^{2n}}} \right)}^{1/n}}\]is equal to: [JEE Main Solved Paper-2016 ]

    A) \[3\log 3-2\]                      

    B) \[\frac{18}{{{e}^{4}}}\]

    C) \[\frac{27}{{{e}^{2}}}\]                                 

    D) \[\frac{9}{{{e}^{2}}}\]

    Correct Answer: C

    Solution :

                    \[{{e}^{\underset{n\to \infty }{\mathop{\lim }}\,\frac{1}{n}\sum\limits_{r=1}^{2n}{\ell n}\left( 1+\frac{r}{n} \right)}}=\int\limits_{{{e}^{0}}}^{2}{\ln (1+x)dx}\] \[\Rightarrow \]\[{{e}^{((x+1))\{\ell n(x+1)-1\}_{0}^{2}}}={{e}^{3\ell n3-2}}=\frac{27}{{{e}^{2}}}\]


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