Which gas has the largest average kinetic energy

Consider two gases A and B in separate 1.0 L containers at the same temperature and pressure. The total mass of gas A in the container is 0.25 g and the mass of gas B in the container is 0.51 g.A. Which gas has the largest average kinetic energy?B.which gas has the fastest root-mean-square speed?C. How can the pressure in the two containers be equal to each other since the larger gas B molecules collide with the container walls more forcefully?