$\%$ of glycine $$\begin{gathered} =\frac{\mathrm{Number} \mathrm{of} \mathrm{molecules} \mathrm{of} \mathrm{glycine}\times \mathrm{molecular} \mathrm{weight} \mathrm{of} \mathrm{glycin}}{\mathrm{Molecular} \mathrm{mass} \mathrm{of} \mathrm{protein}}\times 100 \\ =\left[\frac{75\times 1}{\mathrm{GMM}}\right]\times 100=0.3 \end{gathered}$$

For minimum molecular mass of protein we can take number of molecules of glycine as one. since it can not have less than one molecule.

$\mathrm{GMM}=\left[\frac{75\times 100}{0.3}\right]=25\times {10}^3$