Empirical Formula Sum

Urgently Required solution........
A hydrocarbon contains 4.8g of carbon per gm of hydrogen.Calculate:
a)Gram atom of each
b)Find the Empirical formula
c)Molecular formula if its vapour density is 29
Thanks early action will be appreciated.

carbon ---> 4.8 g / 12.0 g/mol = 0.4 mol
hydrogen ---> 1.0 g / 1.0 g/mol = 1.0 mol

carbon ---> 0.4 / 0.4 = 1
hydrogen ---> 1.0 / 0.4 = 2.5

empirical formula ---> C2H5

vapour density is approx 1/2 of molar mass
https://en.wikipedia.org/wiki/Vapour_den…

molar mass = 58

weight of C2H5 = 29

58/29 = 2

molecular formula = C4H10