Calculate the ratio of the mean free path of the molecule of two gases if the ratio of the numbers density per cm3 of the gases is 5:3 and the ratio of the diameters of the molecules of the gases is 4:5

Given ratio of the number density n1n2=53Ratio of the diameters  d1d2=45Mean free path of the molecules of first gas λ1=12πn1d12Similarly mean free path of the second gasλ2=12πn2d22∴Ratio of  λ1 and λ2λ1λ2=n2d22n1d12=35×542λ1λ2=35×54×54=1516