Assertion (A): Introduction of catalyst does not affect position of                          
                        equilibrium.
Reason     (R): For a reversible reaction, presence of a catalyst influences       
                         both forward & backward reaction to same extent.

When a catalyst is present, the equilibrium is achieved faster but its magnitude remains unaffected. Thus the value of the equilibrium constant in presence of a catalyst is same as in absence of catalyst.
This is because, the catalyst influences the rate of forward reaction and reverse reaction to same extent.

Catalyst influences  $K_f and K_b$ to same extent