Reasoning and Problem Solving
What this domain tests
Reasoning and problem-solving items ask you to draw valid conclusions from given information, spot logical errors, sequence steps, and choose the most effective solution. Formats include deductive puzzles, 'if-then' rules, and practical decisions with constraints.
Concepts to master
- Deduction: if the rule says all A are B, and X is A, then X is B; but the reverse is not automatically true.
- Necessary vs. sufficient conditions: some conditions are required, others are enough on their own.
- Ordering and constraints: arrange items given rules like 'A before B' and 'C not first.'
- Elimination: use the options and rules to rule out answers.
- Assumptions and evidence: separate what is stated from what is assumed.
- Practical problem solving: identify the goal, list constraints, pick the option that meets all of them.
Traps to expect
- Affirming the consequent (assuming the reverse of a rule).
- Options that satisfy most rules but break one.
- Confusing correlation with cause.
- Overlooking a hidden constraint in the question stem.
Worked example / rule of thumb
Rule: 'Only certified members may drive the apparatus.' Maria drives the apparatus. Can we conclude she is certified? Yes, because driving requires certification. Now reverse it: 'Carlos is certified.' Does he drive? Not necessarily; certification is necessary, not sufficient. Rule of thumb: underline every constraint, test each option against all of them, and be suspicious of any answer that reverses an 'only if' rule. When a puzzle has ordering rules, write the positions and cross out possibilities as you apply each rule.