How many rings does an alkane have if its formula is c8h12?

In order to find out the number of rings present in the compound, you would need to know the degree of unsaturation present in it. We know that the saturated hydrocarbon is in the form of CnH2n+2. Thus the saturated counterpart of C8H12 is C8H18. You would notice that it has less than 6 hydrogen atoms or 3 hydrogen molecule. Thus the number of rings present in the compound is 3.