c
\(\quad \mathrm{X}=\frac{2 \mathrm{k}^{3} \ell^{2}}{\mathrm{m} \sqrt{\mathrm{n}}}\)

\(\Rightarrow \frac{\Delta \mathrm{X}}{\mathrm{X}}=\frac{3 \Delta \mathrm{k}}{\mathrm{k}}+\frac{2 \Delta \ell}{\ell}+\frac{\Delta \mathrm{m}}{\mathrm{m}}+\frac{1}{2} \frac{\Delta \mathrm{n}}{\mathrm{n}}\)

\(\Rightarrow \%\) uncertanity \(=3(1)+2(2)+3+\frac{1}{2}(4)=12 \%\)