Change in total gas pressure

The question reads:


[![enter image description here](https://i.stack.imgur.com/2XZ41.png)](https://i.stack.imgur.com/2XZ41.png)


For the part were they ask about the total gas pressure, would it be correct to say that the total gas pressure doesn't change? Instead of $0.8$ $atm$ of $N\_2O$, it is now $0.8$ $atm$ of various partial pressures of $N\_2O$, $N\_2$ and $O\_2$?


