AOSB Aptitude cheat sheet

Valid argument: conclusion follows necessarily from premises; a premise's truth is separate from its validity.

'Some A are B' does not imply 'some B are not A' - check direction of the relation before judging.

Necessary condition: without it the claim fails. Sufficient condition: with it the claim holds. Do not swap them.

Watch quantifier scope: 'all', 'most', 'some', 'none' - 'most' means more than half but not all.

Correlation does not entail causation; a passage asserting cause needs a mechanism or controlled comparison.

A claim is falsifiable if some observation could disprove it; unfalsifiable claims cannot be evidence-backed.

Word-in-context questions: substitute each option back into the sentence and test which preserves the passage's logic.

Inference questions allow only what must be true; assumption questions target the unstated premise the argument needs.

Percentage change = (new − old) / old × 100; a rise then equal fall does not return to the original value.

Successive percentage changes multiply: ×1.10 then ×0.90 gives ×0.99, a net 1% loss.

Speed = distance / time; average speed over two equal distances with speeds a and b is 2ab/(a+b), not (a+b)/2.

Work rate adds: if A finishes in a days and B in b days, together they take ab/(a+b) days.

Ratio scaling: divide the total by the sum of ratio parts, then multiply by each part.

Compound interest: A = P(1 + r)^n; simple interest: A = P(1 + rn).

Probability of independent events multiplies; of mutually exclusive events adds.

Sanity-check magnitude first (units, powers of ten) before computing the exact figure.

Count sides, vertices, enclosed regions, and line intersections - these are the most common sequence rules.

Rotation is rigid (shape unchanged); reflection reverses orientation; check chirality to tell them apart.

Alternating sequences: odd-positioned items follow one rule, even-positioned items another.

Track two attributes independently - e.g. shape changes while shading follows its own cycle.

Net folding: opposite faces on a cube net never share an edge; identify opposite pairs first.

Mirror images swap left-right but preserve vertical order; a 180° rotation swaps both axes.

Number of regions cut by n lines in general position is n(n+1)/2 + 1.

When a matrix puzzle stalls, test row-wise and column-wise rules separately before combining.

Critical path: the longest chain of dependent tasks sets the minimum project duration.

Total float = latest start − earliest start; zero float marks a critical task.

Resource levelling trades duration for a smoother, feasible allocation of people and equipment.

Prioritise by urgency × importance; a task that blocks others outranks an isolated one.

Identify the binding constraint first - improving a non-bottleneck step adds no throughput.

Estimate with three points: expected = (optimistic + 4×likely + pessimistic) / 6.

Build in explicit contingency time; a plan with zero slack fails on the first delay.

Work backwards from the deadline to test whether the plan is achievable before committing.

Leaderless group tasks are scored on contribution to the team outcome, not on dominating airtime.

Assign roles explicitly (timekeeper, scribe, presenter) early so the group does not duplicate effort.

Summarise and test agreement aloud: 'so we agree X - anyone disagree?' converts talk into decisions.

Invite quiet members by name; drawing out others counts as a leadership behaviour.

Timebox: agree a checkpoint at the halfway mark and re-plan if the group is behind.

Disagree with the idea, not the person; state the reason and offer an alternative.

In command tasks, confirm the brief, plan briefly, brief the team, then supervise and adjust.

Safety and rule compliance in practical tasks are scored - never shortcut a stated constraint.

STAR structure: Situation, Task, Action, Result - the Result must be concrete and evidenced.

Use 'I' for your own actions and 'we' for team context; interviewers score individual contribution.

Prepare two or three examples per theme: leadership, teamwork, resilience, problem-solving, integrity.

Motivation answers link personal evidence to the role's actual demands, not generic praise.

For weaknesses, state a real one plus the specific corrective step taken and its effect.

Answer the question asked; pause briefly to structure before speaking rather than filling silence.

Values-based questions test judgement: state the principle, then the action it implies.

Close by asking a substantive question about the role or training that shows prior research.