A large irregularly – shaped closed tank is first evacuated and then connected to a 50 litre cylinder containing compressed nitrogen gas. The gas pressure in the cylinder, originally at 21.0 atm, falls to 2.0 atm, after it is connected to the evacuated tank. The volume of the tank is :
(a) 475 litres
(b) 50 litres
(c) 525 litres
(d) 21.45 litres
