What is gas A’s partial pressure?

Question

A balloon has three gases In it, gas A, gas B, and gas C. The total pressure is 5430 torr. If gas B’s partial pressure is 2700 torr and gas C’s partial pressure is 950 torr, what is gas A’s partial pressure?

Answer 1

Use the fact that the total pressure is the sum of the partial pressures, so

 

P_A = P - (P_B + P_C) = [5430 - (2700 + 950)] torr = ? torr