\(Ta\)\(có\):
\(\left(1+2+3+4+...+n\right)\le65000\)
\(\Rightarrow\left(n+1\right).\left[\left(n-1\right):1+1\right]:2\le65000\)
\(\Rightarrow\left(n+1\right).n:2\le65000\)
\(\Rightarrow\left(n+1\right).n\le32500\)
\(\Rightarrow n^2+n\le32500\)
\(\Rightarrow179^2+179\le32500\)
\(\Rightarrow n=179\)