Yes, beer with up to 3.5 % you can buy in a supermarket. Beer above 3.5 % is called strong beer (starköl) which you can only buy at Systembolaget, the governmental alcohol store. Considering a large part of the beer is light beer (lättöl) or folks beer (folköl) below 3.5 %, the amount of beer to cover the 36 % pure alcohol is even higher.