According to Dalton's law of partial pressure: The pressure exerted by a mixture of gases is sum partial pressure of each gas exert on the container.
[tex]P_{total}=p_{1}+p_{2}+p_{3}.......[/tex]
Here we have mixture of three gases so the total pressure of three gases will be sum of their individual or partial pressures
[tex]P_{total}=p_{1}+p_{2}+p_{3}=3345=988+1289+p_{3}[/tex]
Therefore the partial pressure of third gas will be
[tex]p_{3}=3345-(988+1289)=1068mmHg[/tex]
The pressure of gas#3 is 1068mmHg
