Irish Firefighter Aptitude cheat sheet
Irish Firefighter Aptitude · Keep the key ideas within reach.
Verbal Reasoning
A valid deduction must be true in every case where the premises are true; one counterexample disproves it.
Valid forms: modus ponens (If P then Q; P; therefore Q) and modus tollens (If P then Q; not Q; therefore not P).
Invalid forms: affirming the consequent (If P then Q; Q; therefore P) and denying the antecedent (If P then Q; not P; therefore not Q).
Some / not all statements are not reversible: 'Some A are B' does not entail 'Some B are A' when read as 'some but not all'.
Necessary condition: Q is necessary for P when P cannot occur without Q (P implies Q).
Sufficient condition: Q is sufficient for P when Q guarantees P (Q implies P).
In passage questions, the correct option must be supported only by stated text, not by outside knowledge or plausible assumption.
An inference is 'most strongly supported' when it requires the fewest unstated assumptions.
Word-in-context answers must fit both the sentence's grammar and its logical role, not merely be a synonym of the target word.
Numerical Reasoning
Percentage change = (new − old) / old × 100; a rise then equal fall of x% leaves a net loss of x²/100 %.
Speed = distance / time; to convert km/h to m/s multiply by 5/18, and m/s to km/h multiply by 18/5.
Average = sum of values / number of values; the total equals average × count.
Work rate adds: combined time = 1 / (1/a + 1/b) for two workers finishing in a and b hours alone.
Ratio scaling: if a:b = 3:5, total parts = 8, so each part = total / 8.
Compound growth: final = initial × (1 + r)^n; simple growth: final = initial × (1 + rn).
Profit or loss percentage is calculated on cost price unless the question states otherwise.
To estimate, round each figure to one significant figure and adjust direction (round up if the answer must be an upper bound).
Unit consistency: convert all quantities to the same unit before calculating, and check the answer's magnitude for plausibility.
Spatial and Mechanical Reasoning
Rotating a shape 90° clockwise maps (x, y) to (y, −x); 180° maps (x, y) to (−x, −y); 270° clockwise maps (x, y) to (−y, x).
A mirror reflection reverses one axis only; it does not rotate, so handedness (chirality) is preserved only under rotation, not reflection.
Net folds: each fold halves the visible area; the number of holes after punching through n layers equals the number of distinct punch positions × layers.
Gear trains: meshing gears rotate in opposite directions; the ratio of speeds equals the inverse ratio of teeth counts.
Pulley systems: a single fixed pulley changes direction only; a movable pulley halves the effort needed (ideal, frictionless).
Levers: effort × effort arm = load × load arm; a longer effort arm reduces required effort.
Lever classes: class 1 fulcrum between effort and load; class 2 load between fulcrum and effort; class 3 effort between fulcrum and load.
Pressure = force / area; a smaller contact area gives greater pressure for the same force.
A cube has 6 faces, 12 edges, and 8 vertices; an unfolded cube net must have exactly 6 squares in a valid arrangement.
Situational Judgement / Judgement and Decision Making
Priority order in fire scenarios: life safety first, then incident stabilisation, then property conservation.
Follow the chain of command; report to the incident commander rather than acting unilaterally outside one's role.
When two options both seem reasonable, choose the one that addresses the immediate risk and escalates appropriately.
A 'most appropriate' answer respects procedure, safety of self and others, and clear communication, in that order.
Disclose conflicts of interest and defer decisions where personal involvement could bias judgement.
Record and report accurately; withholding or altering information is never the correct response.
Escalate to a supervisor when a situation exceeds one's authority or competence, not when it is merely inconvenient.
In ranking questions, place actions that prevent harm above actions that merely document or tidy up afterwards.
Work-Style / Behavioural (Personality) Questionnaire
Items are typically rated on a Likert scale (e.g., strongly disagree to strongly agree); answer honestly and consistently.
Consistency checks compare similar items phrased positively and negatively; contradictory answers flag unreliable profiles.
Most fire-service profiles favour conscientiousness, teamwork, calmness under pressure, and rule-following.
Social-desirability scales detect implausibly perfect answers; extreme agreement with every item is penalised.
Behavioural items ask about past conduct; situation-based items ask about likely response to a scenario.
There is no single 'correct' answer; responses should reflect genuine tendencies rather than an idealised image.
Answer independently per item; trying to infer what each question is measuring often produces inconsistency.
Speed matters less than accuracy; rushing increases contradictory responses across repeated themes.
Verbal Reasoning
A valid deduction must be true in every case where the premises are true; one counterexample disproves it.
Valid forms: modus ponens (If P then Q; P; therefore Q) and modus tollens (If P then Q; not Q; therefore not P).
Invalid forms: affirming the consequent (If P then Q; Q; therefore P) and denying the antecedent (If P then Q; not P; therefore not Q).
Some / not all statements are not reversible: 'Some A are B' does not entail 'Some B are A' when read as 'some but not all'.
Necessary condition: Q is necessary for P when P cannot occur without Q (P implies Q).
Sufficient condition: Q is sufficient for P when Q guarantees P (Q implies P).
In passage questions, the correct option must be supported only by stated text, not by outside knowledge or plausible assumption.
An inference is 'most strongly supported' when it requires the fewest unstated assumptions.
Word-in-context answers must fit both the sentence's grammar and its logical role, not merely be a synonym of the target word.
Numerical Reasoning
Percentage change = (new − old) / old × 100; a rise then equal fall of x% leaves a net loss of x²/100 %.
Speed = distance / time; to convert km/h to m/s multiply by 5/18, and m/s to km/h multiply by 18/5.
Average = sum of values / number of values; the total equals average × count.
Work rate adds: combined time = 1 / (1/a + 1/b) for two workers finishing in a and b hours alone.
Ratio scaling: if a:b = 3:5, total parts = 8, so each part = total / 8.
Compound growth: final = initial × (1 + r)^n; simple growth: final = initial × (1 + rn).
Profit or loss percentage is calculated on cost price unless the question states otherwise.
To estimate, round each figure to one significant figure and adjust direction (round up if the answer must be an upper bound).
Unit consistency: convert all quantities to the same unit before calculating, and check the answer's magnitude for plausibility.
Spatial and Mechanical Reasoning
Rotating a shape 90° clockwise maps (x, y) to (y, −x); 180° maps (x, y) to (−x, −y); 270° clockwise maps (x, y) to (−y, x).
A mirror reflection reverses one axis only; it does not rotate, so handedness (chirality) is preserved only under rotation, not reflection.
Net folds: each fold halves the visible area; the number of holes after punching through n layers equals the number of distinct punch positions × layers.
Gear trains: meshing gears rotate in opposite directions; the ratio of speeds equals the inverse ratio of teeth counts.
Pulley systems: a single fixed pulley changes direction only; a movable pulley halves the effort needed (ideal, frictionless).
Levers: effort × effort arm = load × load arm; a longer effort arm reduces required effort.
Lever classes: class 1 fulcrum between effort and load; class 2 load between fulcrum and effort; class 3 effort between fulcrum and load.
Pressure = force / area; a smaller contact area gives greater pressure for the same force.
A cube has 6 faces, 12 edges, and 8 vertices; an unfolded cube net must have exactly 6 squares in a valid arrangement.
Situational Judgement / Judgement and Decision Making
Priority order in fire scenarios: life safety first, then incident stabilisation, then property conservation.
Follow the chain of command; report to the incident commander rather than acting unilaterally outside one's role.
When two options both seem reasonable, choose the one that addresses the immediate risk and escalates appropriately.
A 'most appropriate' answer respects procedure, safety of self and others, and clear communication, in that order.
Disclose conflicts of interest and defer decisions where personal involvement could bias judgement.
Record and report accurately; withholding or altering information is never the correct response.
Escalate to a supervisor when a situation exceeds one's authority or competence, not when it is merely inconvenient.
In ranking questions, place actions that prevent harm above actions that merely document or tidy up afterwards.
Work-Style / Behavioural (Personality) Questionnaire
Items are typically rated on a Likert scale (e.g., strongly disagree to strongly agree); answer honestly and consistently.
Consistency checks compare similar items phrased positively and negatively; contradictory answers flag unreliable profiles.
Most fire-service profiles favour conscientiousness, teamwork, calmness under pressure, and rule-following.
Social-desirability scales detect implausibly perfect answers; extreme agreement with every item is penalised.
Behavioural items ask about past conduct; situation-based items ask about likely response to a scenario.
There is no single 'correct' answer; responses should reflect genuine tendencies rather than an idealised image.
Answer independently per item; trying to infer what each question is measuring often produces inconsistency.
Speed matters less than accuracy; rushing increases contradictory responses across repeated themes.
Verbal Reasoning
A valid deduction must be true in every case where the premises are true; one counterexample disproves it.
Valid forms: modus ponens (If P then Q; P; therefore Q) and modus tollens (If P then Q; not Q; therefore not P).
Invalid forms: affirming the consequent (If P then Q; Q; therefore P) and denying the antecedent (If P then Q; not P; therefore not Q).
Some / not all statements are not reversible: 'Some A are B' does not entail 'Some B are A' when read as 'some but not all'.
Necessary condition: Q is necessary for P when P cannot occur without Q (P implies Q).
Sufficient condition: Q is sufficient for P when Q guarantees P (Q implies P).
In passage questions, the correct option must be supported only by stated text, not by outside knowledge or plausible assumption.
An inference is 'most strongly supported' when it requires the fewest unstated assumptions.
Word-in-context answers must fit both the sentence's grammar and its logical role, not merely be a synonym of the target word.
Numerical Reasoning
Percentage change = (new − old) / old × 100; a rise then equal fall of x% leaves a net loss of x²/100 %.
Speed = distance / time; to convert km/h to m/s multiply by 5/18, and m/s to km/h multiply by 18/5.
Average = sum of values / number of values; the total equals average × count.
Work rate adds: combined time = 1 / (1/a + 1/b) for two workers finishing in a and b hours alone.
Ratio scaling: if a:b = 3:5, total parts = 8, so each part = total / 8.
Compound growth: final = initial × (1 + r)^n; simple growth: final = initial × (1 + rn).
Profit or loss percentage is calculated on cost price unless the question states otherwise.
To estimate, round each figure to one significant figure and adjust direction (round up if the answer must be an upper bound).
Unit consistency: convert all quantities to the same unit before calculating, and check the answer's magnitude for plausibility.
Spatial and Mechanical Reasoning
Rotating a shape 90° clockwise maps (x, y) to (y, −x); 180° maps (x, y) to (−x, −y); 270° clockwise maps (x, y) to (−y, x).
A mirror reflection reverses one axis only; it does not rotate, so handedness (chirality) is preserved only under rotation, not reflection.
Net folds: each fold halves the visible area; the number of holes after punching through n layers equals the number of distinct punch positions × layers.
Gear trains: meshing gears rotate in opposite directions; the ratio of speeds equals the inverse ratio of teeth counts.
Pulley systems: a single fixed pulley changes direction only; a movable pulley halves the effort needed (ideal, frictionless).
Levers: effort × effort arm = load × load arm; a longer effort arm reduces required effort.
Lever classes: class 1 fulcrum between effort and load; class 2 load between fulcrum and effort; class 3 effort between fulcrum and load.
Pressure = force / area; a smaller contact area gives greater pressure for the same force.
A cube has 6 faces, 12 edges, and 8 vertices; an unfolded cube net must have exactly 6 squares in a valid arrangement.
Situational Judgement / Judgement and Decision Making
Priority order in fire scenarios: life safety first, then incident stabilisation, then property conservation.
Follow the chain of command; report to the incident commander rather than acting unilaterally outside one's role.
When two options both seem reasonable, choose the one that addresses the immediate risk and escalates appropriately.
A 'most appropriate' answer respects procedure, safety of self and others, and clear communication, in that order.
Disclose conflicts of interest and defer decisions where personal involvement could bias judgement.
Record and report accurately; withholding or altering information is never the correct response.
Escalate to a supervisor when a situation exceeds one's authority or competence, not when it is merely inconvenient.
In ranking questions, place actions that prevent harm above actions that merely document or tidy up afterwards.
Work-Style / Behavioural (Personality) Questionnaire
Items are typically rated on a Likert scale (e.g., strongly disagree to strongly agree); answer honestly and consistently.
Consistency checks compare similar items phrased positively and negatively; contradictory answers flag unreliable profiles.
Most fire-service profiles favour conscientiousness, teamwork, calmness under pressure, and rule-following.
Social-desirability scales detect implausibly perfect answers; extreme agreement with every item is penalised.
Behavioural items ask about past conduct; situation-based items ask about likely response to a scenario.
There is no single 'correct' answer; responses should reflect genuine tendencies rather than an idealised image.
Answer independently per item; trying to infer what each question is measuring often produces inconsistency.
Speed matters less than accuracy; rushing increases contradictory responses across repeated themes.