UPSC CDS I 2019 Math Paper

In this question, we are going to check the inequality 3N>N3 by putting the value of N = 1, 2 and 3. When N = 1:
31>13 is true
When N=2
32>23
⇒9 > 8 is true
Thus, we see that inequality 3N>N3 holds true for every natural number except N = 3.