The gase in a mixture have the following partial pressures at the same volume and temperature, 1013000Pa nitrogen, 700mm argon, 1.20atm helium, 790 torr oxygen, and 0.50 atm of carbon dioxide. What is the total pressure of tyhe mixture in atm?

You add them. You will have to convert units to the same units.

760torr= 1atm= 101.3kPa= 760mmHg