Find the ratio of De-Broglie wavelength of molecules of hydrogen and helium which are at temperatures $\;27^{0} C \;and\; 127^{0} C \;$ respectively

Question

$(a)\;\sqrt{\large\frac{2}{3}}\qquad(b)\;\sqrt{\large\frac{8}{3}}\qquad(c)\;\sqrt{\large\frac{1}{3}}\qquad(d)\;\sqrt{\large\frac{4}{3}}$

Comments

Why u take mass of hydrogen is 2, it is 1!!!