76. Two thermally insulated vessels 1 and 2 are filled with air at temperatures

( T₁,T₂) volume (V₁,V₂)  and pressure (P₁,P₂) respectively. If the valve joining the two vessels is opened, the temperature inside the vessel at equilibrium will be

(a)  T₁ +T₂                                                                          (b)  (T₁ +T₂  )/2

(c) [T₁T₂( P₁V₁ + P₂ V₂)]/(  P₁V₁T₂ + P₂ V₂ T₁ )          (d) [T₁T₂( P₁V₁ + P₂ V₂)]/(  P₁V₁T1 + P₂ V₂ T₂ )

Answer-c