A π420Lπ tank contains steam, initially at π400⁰ C,3π bar. A valve is opened for 20 seconds and steam flows out of the tank at a constant mass flow rate of π0.005π πk(g)(s)π. During steam removal, a heater maintains the temperature inside the tank at π400⁰ Cπ. If the final pressure in the tank is π2π bar, determine the mass of steam remaining in the tank after 20 seconds.
a) π0.75π kg
b) π1.00π kg
c) π1.25π kg
d) π1.50π kg