By binary codes or a whole image depending on the description of the image.
You got the answer correct. If you would double check
given:C (12 g/mol) H (1 g/mol).
12(8) + 1(8) = 104 g/mol
and for C2H4
12(2)+1(4) = 28g/mol
Also, chemical formula of styrene is<span> C6H5CH=CH2.</span>
Here...see the attachment