Which one of the following is the kinetic energy of a gaseous mixture containing 3 g of hydrogen and 80 g of oxygen at temperature T(K) ?

Kinetic energy=$\frac{3}{2}\mathrm{nRT}$

Number of moles of hydrogen=3/2=1.5

Number of moles of oxygen=80/32=2.5

Total number of moles=1.5+2.5=4

Kinetic energy=$\frac{3}{2}4\mathrm{RT}$

Kinetic energy=6RT

Hence the required option is B