What is the total pressure, in atmospheres, of a 10.0 L container that contains 10 moles of nitrogen gas and 10 moles of oxygen gas at 300 K?

I tried using PV=nRT and added both P together but kept getting the wrong answer.
n=10, T=300 K, V=1x10^-3 m^3

1 answer

A.24.6L
B.49.3L
C.2460L
D.4930L