Find the value of \[\gamma =\frac{{{C}_{p}}}{{{C}_{V}}}\] for a mixture consisting of \[{{n}_{1}}\] moles of a monoatomic gas and \[{{n}_{2}}\] moles of a gas of diatomic molecules:

• A. \[\frac{{{n}_{1}}}{{{n}_{2}}}\]
• B. \[\frac{5{{n}_{1}}+7{{n}_{2}}}{3{{n}_{1}}+5{{n}_{2}}}\]
• C. \[\frac{3{{n}_{1}}+5{{n}_{2}}}{5{{n}_{1}}+7{{n}_{2}}}\]
• D. \[\frac{7{{n}_{1}}+3{{n}_{2}}}{5{{n}_{1}}+3{{n}_{2}}}\]