0 votes 0 votes Let $n \geq 3$ be an integer. Then the statement $(n!)^{1/n} \leq \dfrac{n+1}{2}$ is true for every $n \geq 3$ true if and only if $n \geq 5$ not true for $n \geq 10$ true for even integers $n \geq 6$, not true for odd $n \geq 5$ Quantitative Aptitude isi2017-mmamma quantitative-aptitude factorial inequality + – go_editor asked Sep 15, 2018 • edited Nov 19, 2019 by Lakshman Bhaiya go_editor 318 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 2 votes 2 votes By AM-GM inequality, We have $$\sqrt[n]{1\cdot2\cdot3\cdot...\cdot n}\le\frac{1+2+3+...+n}{n}=\frac{n(n+1)}{2n}=\frac{n+1}{2}$$ $\Rightarrow ( n!)^{\frac{1}{n}}\leq \frac{n+1}{2}$ Hence, Option $(A)$ is correct. N answered Apr 11, 2019 • selected Apr 11, 2019 by ankitgupta.1729 N comment Share Follow See all 0 reply Please log in or register to add a comment.