Answer: sum of the pressure of the two gases present.
Step-by-step explanation:
According to Dalton's law, the total pressure of a mixture of gases is the sum of individual pressures exerted by the constituent gases.
For example if there are there are two gases hydrogen and oxygen with individual pressure of 30 and 20 atm each. Then the total pressure in the container will be:
Thus

Thus if two gases are present in a container, the total pressure in the container is equal to sum of the pressure of the two gases present.