At 1000 K the N2(g) and O2(g) in air (78% N2, 21% O2, by moles) react to

Question:

At 1000 K the N2(g) and O2(g) in air (78% N2, 21% O2, by moles) react to form a mixture of NO(g) and NO2(g). The values of the equilibrium constants are 1.5 × 10-4 and 1.0 × 10-5 for the formation of NO(g) and NO2(g), respectively. At what total pressure will the partial pressures of NO(g) and NO2(g) be equal in an equilibrium mixture of N2(g), O2(g), NO(g), and NO2(g)?