Answer:
13.3 atm(assuming the temperature given is in Celsius)
Step-by-step explanation:
First, the moles of each gas must be found. .25 mol He, .50 mol CO, .33 mol NO. Next, each set of mols must be plugged into the ideal gas law, PV=nRT, for each gas. Move it around so you get the pressure P=nRT/V. When you calculate everything, you should get 3.08atm He, 6.15atm CO, and 4.06atm NO. Add these together and you get the pressure of the container.