Answer
\begin{equation}
n=81000
\end{equation}
Work Step by Step
\begin{array}{l}{\text { The value of } n \text { for which the number of instructions executed is the same is }} \\ {\text { given by: }} \\ {\qquad 0.003 n^{2}=243 n \Longrightarrow n=81000} \\ {\text { Thus, for } n>81000, \text { The linear time algorithm is more efficient than the }} \\ {\text { quadratic algorithm. }}\end{array}