Answer:
67.1 atm
Explanation:
From Dalton's law of Partial Pressures, the total partial pressure equals the sum of the individual partial pressures.
P = P₁ + P₂ + P₃
P₁ = 38.39 atm of O₂
P₂ = 3.38 atm of He
P₃ = 25.33 atm of N₂
So, P = P₁ + P₂ + P₃ = 38.39 atm + 3.38 atm + 25.33 atm = 67.1 atm