Since October 2004, Jack Daniels Tennessee whisky, produced in Lynchburg, TN, has been bottled at 80 proof (40% alcohol by volume). Given that the density of ethyl alcohol is 0.789 g/cm3, and that of water 1.00 g/cm3, calculate the concentration of the alcohol in (a) percent by weight and (b) molarity (moles per liter).