c
\({A_1} = \,\,{\lambda _1}\,{N_1}\)  અને \({A_2} = \,\,{\lambda _2}{N_2}\)

\({A_1} = \,{A_2}\, \)

\(\Rightarrow \,\,\frac{{0.693}}{{{T_1}}}\,\,{N_1} = \,\,\frac{{0.693}}{{{T_2}}}\,{N_2}\,\,\)

\(\, \Rightarrow \,\,\frac{{{N_1}}}{{{T_1}}} = \,\,\frac{{{N_2}}}{{{T_2}}}\,\,\,\)

\(\Rightarrow \,\,\frac{{{N_1}}}{{{N_2}}}\,\, = \,\,\frac{3}{{27}}\,\, = \,\,\frac{1}{9}\)

\({N_1}:{N_2}\,\, = \,\,1:\,\,9\)