A symbol of vitamin A c20h30o contain 4into 10power 22 carbon atom .how many atom of H and how many molecules of vitamin do it contains

Answer 1

I assume this is what you meant.
A sample of vitamin A (C20H30O) contains 4 x 10^22 carbon atoms.
How many atoms of H and how many molecules of vitamin A does it contain?

There are shorter ways to do this but the long way is easier to see.
1 mol C20H30O contains 6.02E23 molecules C20H30O) and 20*6.02E23 atoms C= 1.2E25 atoms C. The sample contains 4E22 Carbon atoms from the problem so 4E22 atoms C/1.2E25 = 3.33E-3 mols C20H30O. The number of molecules then is 3.33E-3 mols x 6.02E23 molecules/mol = ?
You can apply the same procedure to determine the number of H atoms in the sample.