Partial pressure of Ar = 92.934 kPa
Partial pressure of a gas = Mole fraction × Total pressure
Mole fraction = Number of moles of a gas /Total moles of gas
Therefore;
Mole fraction of Ar = 0.211 mol/ (0.211 + 0.150)
= 0.5845
Total pressure = 159 kPa
Hence;
Partial pressure of Ar = 0.5845 × 159 kPa
= 92.934 kPa