Two Monoatomic Gases,helium and Neon,are Mixed in the Ratio of 2

Multiple Choice

Two monoatomic gases,helium and neon,are mixed in the ratio of 2 to 1 and are in thermal equilibrium at temperature T (the molar mass of helium = 4.0 g/mol and the molar mass of neon = 20.2 g/mol) .If the average kinetic energy of each helium atom is 6.3 $\times$ 10^-21 J,calculate the temperature T.

A) 304 K
B) 456 K
C) 31 K
D) 31 ^$\circ$ C
E) 101 K