Molecular formular for C3H8O ( Isopropyl alcohol)
comprises of 3 Carbon, 8 Hydrogen and 1 oxygen ,
So, first box =3
second box = 8
third box = 1
emperical mass c3h80 =( 3*12) + (1*1) + (1*15.99) = 53.03 g/mole
Molecular formular = molecular weight / emperical mass
= 60.10g/mole /53.03g/mole = 1.133
if we multiply subscripts numbers ; we still get
Molecular formula = C3H8O
However, the second option doesnt have the option of 8 hydrogen .