What is the temperature at which the kinetic energy of 0.3 moles of Helium is equal to the kinetic energy of $0.4$ moles of Argon at 400 k?

Question

\[\begin {array} {1 1} (1)\;400\;k & \quad (2)\;873\;k \\ (3)\;533\;k & \quad (4)\;300\;k \end {array}\]