Logical Reasoning - Flashcards
Master the fundamentals of logical reasoning with these comprehensive flashcards covering arguments, deductive and inductive reasoning, syllogisms, diagrammatic methods, and problem-solving strategies essential for the Civil Service Examination.
Flashcards
What is the definition of Logic?
Answer
Logic is the study of correct versus incorrect reasoning. It helps us distinguish between valid and invalid arguments, and provides systematic methods for analyzing how conclusions follow from premises.
What are the three components of an argument?
Answer
An argument consists of: 1) Premises - statements that provide reasons for accepting the conclusion, 2) Conclusion - the statement that is established by the premises, and 3) Assumption - any unstated premise in the argument.
What is a Deductive Argument and what approach does it use?
Answer
A deductive argument starts with general statements to reach specific conclusions. It uses a 'top-down' approach. If the premises are true, the conclusion must also be true. The conclusion is fully supported by the premises, making the argument either valid or invalid.
Analyze this deductive argument: 'All zombies crave human flesh. Anne is a zombie. Therefore, Anne craves human flesh.'
Answer
This is a valid deductive argument. The major premise establishes a universal rule about zombies, the minor premise identifies Anne as a zombie, and the conclusion logically follows. Since both premises are accepted as true, the conclusion must be true.
What is an Inductive Argument and how does it differ from deductive reasoning?
Answer
Inductive argument starts from specific observations to reach broad generalizations using a 'bottom-up' approach. The conclusion is PROBABLY supported by premises, not definitely. It uses terms like 'probably,' 'likely,' 'possibly' rather than definitive statements. Additional premises can strengthen or weaken the argument.
What is a Categorical Syllogism?
Answer
A categorical syllogism follows the format: If A is B (1st premise) and B is C (2nd premise), therefore A is C (conclusion). It uses three terms: major term (appears in premise and conclusion predicate), minor term (appears in premise and conclusion subject), and middle term (appears in both premises but not conclusion).
What is a Disjunctive Syllogism?
Answer
Disjunctive syllogism deals with exclusive alternatives. Format: 'A is either B or C (major premise). A is not C (minor premise). Therefore, A is B (conclusion).' The premises are mutually exclusive, and eliminating one option confirms the other.
What are the two valid formats for Conditional Syllogism?
Answer
Format 1: If A is true, then B is true. A is true. Therefore, B is true (Modus Ponens). Format 2: If A is true, then B is true. B is NOT true. Therefore, A is NOT true (Modus Tollens). Both require at least one conditional premise accepted as true.
When using Venn diagrams, how do you represent 'All As are Bs'?
Answer
Draw circle A completely inside circle B. This shows that the entire set A is contained within set B. The relationship cannot be reversed (All Bs are As would be incorrect unless specifically stated).
How do you represent 'Some As are Bs' using Venn diagrams?
Answer
Draw two intersecting circles A and B with overlapping area. The intersection represents elements that belong to both sets. Neither circle is completely inside the other, indicating partial relationship only.
What are the four steps for diagramming character problems?
Answer
Step 1: Make a line and assign direction for character placement. Step 2: Write the first character in the middle. Step 3: Analyze each statement and place characters based on comparisons. Step 4: Create conclusion based on the diagram.
What is the 'Working Backwards' strategy in problem solving?
Answer
Working backwards involves starting from the final result and reversing operations to find the initial value. Use opposite operations: if the problem adds, you subtract; if it multiplies, you divide. Construct a table showing information, steps, and results for clear visualization.
What is the 'Make an Organized List' strategy?
Answer
This strategy involves laying out all possible values and using systematic elimination. List all possibilities that meet the first condition, then eliminate options that don't satisfy subsequent conditions. It's a methodical trial-and-error approach.
What are the key characteristics of a Repeating Pattern?
Answer
A repeating pattern has a constant value that influences the flow throughout the sequence. Only one operation is used to determine each succeeding value. Example: 1, 3, 5, 7, 9, 11 (adding 2 each time).
How does an Increasing/Decreasing Pattern work?
Answer
Numbers change through values that are successively increasing or decreasing by a constant value. The difference between consecutive terms forms its own arithmetic sequence. Example: 2, 4, 7, 11, 16, 22 (differences: +2, +3, +4, +5, +6).
What defines an Alternating Pattern?
Answer
An alternating pattern combines two or more other patterns that alternate throughout the sequence. Values, operations, and terms may alternate. Example: 2, 4, 6, 9, 11, 15, 22 (alternates between +2 and increasing differences).
How do you solve Sudoku puzzles effectively?
Answer
Key strategies: 1) Check column, row, and set before entering numbers to avoid duplicates, 2) Sum of all numbers in any complete line/set should equal 45 (for 9x9), 3) List possible numbers for difficult boxes and use elimination, 4) Start with lines that have only one missing number.
What is a Magic Square and how do you solve it?
Answer
A magic square is a puzzle where numbers are placed so any row, column, or diagonal adds up to the same magic sum. Strategy: Look for rows/columns/diagonals with only one missing number, solve those first, then work systematically through remaining positions.
What are the key steps for reading and analyzing flowcharts?
Answer
- Read the entire flowchart first to understand all possible scenarios, 2) Don't focus on just one step - look at preceding and succeeding steps, 3) For questions about outcomes, work backwards from the result to trace the path, 4) Consider all decision points that lead to the conclusion.
Compare Deductive vs Inductive Reasoning approaches and certainty levels.
Answer
Deductive: Top-down approach, moves from general to specific, conclusions are certain if premises are true, uses valid/invalid terminology. Inductive: Bottom-up approach, moves from specific to general, conclusions are probable, uses likely/probably terminology, can be strengthened or weakened by additional evidence.
Diagrams
Logical Reasoning Concept Map
Comprehensive overview of logical reasoning concepts showing the relationship between different types of reasoning, visual methods, and problem-solving approaches.
Argument Analysis Process
Step-by-step flowchart for analyzing arguments, determining their type, and evaluating their strength or validity.
Problem Solving Strategy Selection
Decision flowchart for selecting the most appropriate problem-solving strategy based on the type of logical reasoning problem presented.