Logical Reasoning for Public Service Exams

This course is for Brazilian public service exams (concursos públicos) and the lessons are taught in Portuguese. Logical reasoning is the subject that scares exam candidates the most, and almost always for the wrong reason: people think they need to be good at math, when what they really need is a method. This course starts from zero and shows that method with Professora Helena, one question at a time. Part one is propositions and connectives: what is and is not a proposition, and how and, or, if-then and if-and-only-if work. Part two is truth tables and equivalences: building the table without getting lost, recognizing tautology and contradiction, and the equivalences exam boards test most, such as the contrapositive. Part three is negation and quantifiers: negating a compound sentence with De Morgan laws, negating if-then, and dealing with all, some and none. Part four is sequences and logic problems: finding the pattern in a sequence, organizing data in an association table and solving truth-teller and liar problems. The last part is counting and probability: the multiplication principle, permutation, arrangement, combination and probability as favorable cases over possible cases. The questions follow the exam-board style, with True or False and multiple choice, and every answer comes with the full reasoning.