Liquid reactant A decomposes as follows

A $\rightarrow$ R r${_R} $= k${_1}$C$^{2}$${_A}$ k${_1}$ = 0.5m$^{3}$/mol-s

A $\rightarrow$ S r${_S} $= k${_2}$C${_A}$ k${_2}$ = 1 s$^{-1}$

What is the % conversion of A, to the nearest integer, so that the concentration of S in the exit stream is 11.8 mol/m$^{3}$? $\_\_\_ \_\_\_\_$