{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2026-05-26T00:16:20.000Z","description":"Problems submitted by members of the MATLAB Central community.","is_default":true,"created_by":161519,"badge_id":null,"featured":false,"trending":false,"solution_count_in_trending_period":0,"trending_last_calculated":"2026-05-26T00:00:00.000Z","image_id":null,"published":true,"community_created":false,"status_id":2,"is_default_group_for_player":false,"deleted_by":null,"deleted_at":null,"restored_by":null,"restored_at":null,"description_opc":null,"description_html":null,"published_at":null},"problems":[{"id":1146,"title":"Calculate Alcohol By Volume with Original and Final Gravity","description":"Given an initial gravity of un-fermented wort (OG) and a final gravity of fermented wort (FG), better known as beer, it is possible to get the general ABV (will be a %).\r\n\r\nNote: Any wort that gets denser through fermentation will appear to have a negative ABV; in those cases the ABV should be marked as 0.  Most brews do not have a lot of room on the label so round to the 2nd decimal place.  Assume a constant of 131 is involved (this is why it is only a general ABV).\r\n\r\nExample:\r\n\r\nx = [OG FG] = [1.085 1.009]\r\n\r\nABV = (OG-FG)*131 = 9.96%","description_html":"\u003cp\u003eGiven an initial gravity of un-fermented wort (OG) and a final gravity of fermented wort (FG), better known as beer, it is possible to get the general ABV (will be a %).\u003c/p\u003e\u003cp\u003eNote: Any wort that gets denser through fermentation will appear to have a negative ABV; in those cases the ABV should be marked as 0.  Most brews do not have a lot of room on the label so round to the 2nd decimal place.  Assume a constant of 131 is involved (this is why it is only a general ABV).\u003c/p\u003e\u003cp\u003eExample:\u003c/p\u003e\u003cp\u003ex = [OG FG] = [1.085 1.009]\u003c/p\u003e\u003cp\u003eABV = (OG-FG)*131 = 9.96%\u003c/p\u003e","function_template":"function y = brew_ABV(x)\r\n  y = x;\r\nend","test_suite":"%% Nice strong beer\r\nx = [1.085 1.005];\r\ny_correct = 10.48;\r\nassert(isequal(brew_ABV(x),y_correct))\r\n\r\n%% Regular ale\r\nx = [1.063 1.01];\r\ny_correct = 6.94;\r\nassert(isequal(brew_ABV(x),y_correct))\r\n\r\n%% Water with sugar added?\r\nx = [1.00 1.02];\r\ny_correct = 0;\r\nassert(isequal(brew_ABV(x),y_correct))\r\n\r\n%% Water\r\nx = [1.00 1.00];\r\ny_correct = 0;\r\nassert(isequal(brew_ABV(x),y_correct))","published":true,"deleted":false,"likes_count":1,"comments_count":0,"created_by":9554,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":79,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2012-12-28T15:06:33.000Z","updated_at":"2026-02-27T22:21:12.000Z","published_at":"2012-12-28T15:09:11.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eGiven an initial gravity of un-fermented wort (OG) and a final gravity of fermented wort (FG), better known as beer, it is possible to get the general ABV (will be a %).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eNote: Any wort that gets denser through fermentation will appear to have a negative ABV; in those cases the ABV should be marked as 0. Most brews do not have a lot of room on the label so round to the 2nd decimal place. Assume a constant of 131 is involved (this is why it is only a general ABV).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eExample:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ex = [OG FG] = [1.085 1.009]\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eABV = (OG-FG)*131 = 9.96%\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"problem_search":{"problems":[{"id":1146,"title":"Calculate Alcohol By Volume with Original and Final Gravity","description":"Given an initial gravity of un-fermented wort (OG) and a final gravity of fermented wort (FG), better known as beer, it is possible to get the general ABV (will be a %).\r\n\r\nNote: Any wort that gets denser through fermentation will appear to have a negative ABV; in those cases the ABV should be marked as 0.  Most brews do not have a lot of room on the label so round to the 2nd decimal place.  Assume a constant of 131 is involved (this is why it is only a general ABV).\r\n\r\nExample:\r\n\r\nx = [OG FG] = [1.085 1.009]\r\n\r\nABV = (OG-FG)*131 = 9.96%","description_html":"\u003cp\u003eGiven an initial gravity of un-fermented wort (OG) and a final gravity of fermented wort (FG), better known as beer, it is possible to get the general ABV (will be a %).\u003c/p\u003e\u003cp\u003eNote: Any wort that gets denser through fermentation will appear to have a negative ABV; in those cases the ABV should be marked as 0.  Most brews do not have a lot of room on the label so round to the 2nd decimal place.  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