Internal energy of n1 moles of hydrogen of temperature T is equal to the internal energy of n2 mole of helium at temperature 2T.Then the ratio n1n2 is

Internal energy of a n moles of an ideal gas at temperature T is given by  U = f2nRT [f = degress of freedom]U1 = U2f1n1T1 = f2n2T2∴ n1n2 = f2T2f1T1 = 3×25×1 = 65Here, f2 = degrees of freedom of He = 3 and f1 = degrees of freedome of H2 = 5