{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2026-06-05T00:10:21.000Z","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":"2026-06-05T00:00:00.000Z","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":44696,"title":"Sum of unique multiples of 3 and 5","description":"If we list all the natural numbers up to 15 that are multiples of 3 or 5, we get 3, 5, 6, 9, 10, 12 and 15. The sum of these multiples is 60. \r\n\r\nWrite a function called _*sum3and5muls*_ that returns the sum of all the unique multiples of 3 or 5 up to n where n is a positive integer and the only input argument of the function.","description_html":"\u003cp\u003eIf we list all the natural numbers up to 15 that are multiples of 3 or 5, we get 3, 5, 6, 9, 10, 12 and 15. The sum of these multiples is 60.\u003c/p\u003e\u003cp\u003eWrite a function called \u003ci\u003e\u003cb\u003esum3and5muls\u003c/b\u003e\u003c/i\u003e that returns the sum of all the unique multiples of 3 or 5 up to n where n is a positive integer and the only input argument of the function.\u003c/p\u003e","function_template":"function sum_mult = sum3and5muls(n)\r\n    sum_mult\r\nend","test_suite":"%%\r\nn = 15;\r\nsm_correct = 60;\r\nassert(isequal(sum3and5muls(n),sm_correct))\r\n\r\n%%\r\nn = 18;\r\nsm_correct = 78;\r\nassert(isequal(sum3and5muls(n),sm_correct))\r\n\r\n%%\r\nn = (2^2)-1;\r\nsm_correct = 3;\r\nassert(isequal(sum3and5muls(n),sm_correct))\r\n\r\n%%\r\nn = randi(25);\r\nsm_correct = sum(3:3:n)+sum(5:5:n)-sum(15:15:n);\r\nassert(isequal(sum3and5muls(n),sm_correct))\r\n","published":true,"deleted":false,"likes_count":1,"comments_count":0,"created_by":171559,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":62,"test_suite_updated_at":"2018-07-10T11:40:12.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2018-07-10T11:35:26.000Z","updated_at":"2026-05-30T00:39:12.000Z","published_at":"2018-07-10T11:40:12.000Z","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\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"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\\n\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\u003eIf we list all the natural numbers up to 15 that are multiples of 3 or 5, we get 3, 5, 6, 9, 10, 12 and 15. The sum of these multiples is 60.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eWrite a function called\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003esum3and5muls\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e that returns the sum of all the unique multiples of 3 or 5 up to n where n is a positive integer and the only input argument of the function.\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\"}]}"},{"id":44707,"title":"Raise each element to the power of its index in a matrix","description":"In a matrix, A = [1,2;3,4]\r\nraise the power of each element like: 1^1+2^3+3^2+4^4 and add it all to produce the result 274\r\n\r\n","description_html":"\u003cp\u003eIn a matrix, A = [1,2;3,4]\r\nraise the power of each element like: 1^1+2^3+3^2+4^4 and add it all to produce the result 274\u003c/p\u003e","function_template":"function y = matrix_pow(x)\r\n\r\nend","test_suite":"%%\r\nx = [1,2;3,4];\r\ny_correct = 274;\r\nassert(isequal(matrix_pow(x),y_correct))\r\n\r\n%%\r\nx = [1 7 8 -9];\r\ny_correct = 7123;\r\nassert(isequal(matrix_pow(x),y_correct))\r\n\r\n%%\r\nx = eye(3).*8;\r\ny_correct = 134250504;\r\nassert(isequal(matrix_pow(x),y_correct))","published":true,"deleted":false,"likes_count":1,"comments_count":0,"created_by":171559,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":54,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2018-08-03T09:00:18.000Z","updated_at":"2026-05-30T00:33:05.000Z","published_at":"2018-08-03T09:18:08.000Z","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\u003eIn a matrix, A = [1,2;3,4] raise the power of each element like: 1^1+2^3+3^2+4^4 and add it all to produce the result 274\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":44696,"title":"Sum of unique multiples of 3 and 5","description":"If we list all the natural numbers up to 15 that are multiples of 3 or 5, we get 3, 5, 6, 9, 10, 12 and 15. The sum of these multiples is 60. \r\n\r\nWrite a function called _*sum3and5muls*_ that returns the sum of all the unique multiples of 3 or 5 up to n where n is a positive integer and the only input argument of the function.","description_html":"\u003cp\u003eIf we list all the natural numbers up to 15 that are multiples of 3 or 5, we get 3, 5, 6, 9, 10, 12 and 15. The sum of these multiples is 60.\u003c/p\u003e\u003cp\u003eWrite a function called \u003ci\u003e\u003cb\u003esum3and5muls\u003c/b\u003e\u003c/i\u003e that returns the sum of all the unique multiples of 3 or 5 up to n where n is a positive integer and the only input argument of the function.\u003c/p\u003e","function_template":"function sum_mult = sum3and5muls(n)\r\n    sum_mult\r\nend","test_suite":"%%\r\nn = 15;\r\nsm_correct = 60;\r\nassert(isequal(sum3and5muls(n),sm_correct))\r\n\r\n%%\r\nn = 18;\r\nsm_correct = 78;\r\nassert(isequal(sum3and5muls(n),sm_correct))\r\n\r\n%%\r\nn = (2^2)-1;\r\nsm_correct = 3;\r\nassert(isequal(sum3and5muls(n),sm_correct))\r\n\r\n%%\r\nn = randi(25);\r\nsm_correct = sum(3:3:n)+sum(5:5:n)-sum(15:15:n);\r\nassert(isequal(sum3and5muls(n),sm_correct))\r\n","published":true,"deleted":false,"likes_count":1,"comments_count":0,"created_by":171559,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":62,"test_suite_updated_at":"2018-07-10T11:40:12.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2018-07-10T11:35:26.000Z","updated_at":"2026-05-30T00:39:12.000Z","published_at":"2018-07-10T11:40:12.000Z","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\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"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\\n\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\u003eIf we list all the natural numbers up to 15 that are multiples of 3 or 5, we get 3, 5, 6, 9, 10, 12 and 15. The sum of these multiples is 60.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eWrite a function called\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003cw:i/\u003e\u003c/w:rPr\u003e\u003cw:t\u003esum3and5muls\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e that returns the sum of all the unique multiples of 3 or 5 up to n where n is a positive integer and the only input argument of the function.\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\"}]}"},{"id":44707,"title":"Raise each element to the power of its index in a matrix","description":"In a matrix, A = [1,2;3,4]\r\nraise the power of each element like: 1^1+2^3+3^2+4^4 and add it all to produce the result 274\r\n\r\n","description_html":"\u003cp\u003eIn a matrix, A = [1,2;3,4]\r\nraise the power of each element like: 1^1+2^3+3^2+4^4 and add it all to produce the result 274\u003c/p\u003e","function_template":"function y = matrix_pow(x)\r\n\r\nend","test_suite":"%%\r\nx = [1,2;3,4];\r\ny_correct = 274;\r\nassert(isequal(matrix_pow(x),y_correct))\r\n\r\n%%\r\nx = [1 7 8 -9];\r\ny_correct = 7123;\r\nassert(isequal(matrix_pow(x),y_correct))\r\n\r\n%%\r\nx = eye(3).*8;\r\ny_correct = 134250504;\r\nassert(isequal(matrix_pow(x),y_correct))","published":true,"deleted":false,"likes_count":1,"comments_count":0,"created_by":171559,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":54,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2018-08-03T09:00:18.000Z","updated_at":"2026-05-30T00:33:05.000Z","published_at":"2018-08-03T09:18:08.000Z","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\u003eIn a matrix, A = [1,2;3,4] raise the power of each element like: 1^1+2^3+3^2+4^4 and add it all to produce the result 274\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\"}]}"}],"errors":[],"facets":[[],[{"value":"easy","count":2,"selected":false}]],"term":"tag:\"basic mathematics\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}