c
\(\frac{{{T_2}}}{{{T_1}}}\,\, = \,\,{\left( {\frac{{{P_2}}}{{{P_1}}}} \right)^{\frac{{\gamma - 1}}{\gamma }}}\,\, \Rightarrow \,\,\frac{{{T_2}}}{{{T_1}}}\,\, = \,\,{\left( {\frac{1}{8}} \right)^{\frac{{1.5 - 1}}{{1.5}}}}\)
\(\, = \,\,{\left( {\frac{1}{8}} \right)^{\frac{1}{3}}}\,\, = \,\,\frac{1}{2}\,\, \Rightarrow \,\,{T_2}\,\, = \,\,\frac{{{T_1}}}{2}\, = \,\,\frac{{300}}{2}\)
\(\, = \,\,150\,K\)