Neco Model Questions Vol1 2017 Biology Question 33

At sea level the alveolar partial pressures are \(P_{A\text{O}_2}=100\ \text{mmHg}\) and \(P_{A\text{CO}_2}=40\ \text{mmHg}\). Using the alveolar gas equation \(P_{A\text{O}_2}=F_{i\text{O}_2}(P_B-P_{H_2O})-\frac{P_{A\text{CO}_2}}{R}\) with \(F_{i\text{O}_2}=0.21\), \(P_B=760\ \text{mmHg}\), \(P_{H_2O}=47\ \text{mmHg}\) and respiratory quotient \(R=0.8\) confirms this value. At a high altitude the barometric pressure falls to \(P_B=600\ \text{mmHg}\) and the subject increases alveolar ventilation by 20 % compared with sea level. Assuming the increase in ventilation reduces \(P_{A\text{CO}_2}\) proportionally, calculate the new alveolar \(P_{A\text{O}_2}\) (in mmHg, rounded to the nearest whole number).