Argon gas is approaching a converging-diverging nozzle with a low velocity at 208C and 120 kPa, and

Question:

Argon gas is approaching a converging-diverging nozzle with a low velocity at 208C and 120 kPa, and it leaves the nozzle at a supersonic velocity. If the cross-sectional area of the throat is 0.015 m2, the mass flow rate of argon through the nozzle is
(a) 0.41 kg/s (b) 3.4 kg/s (c) 5.3 kg/s (d ) 17 kg/s (e) 22 kg/s