One hundred kmol/hr of a stream containing 20 mol% CO, 20 mol% H₂O, and 60 mol% H₂ is combined with additional steam and fed to a water-gas-shift reactor to produce more hydrogen according to the reaction: CO + H₂O <->CO₂ + H₂. The equilibrium constant of the water-gas-shift reaction is 200, and the mole fraction of hydrogen at the outlet is 0.75. Using the extent of reaction method, how much additional steam is fed into the water-gas-shift reactor?