DE POST cheat sheet

Percentage change = (new − old) ÷ old × 100; a 20% rise followed by a 20% fall leaves 96% of the original value, not 100%.

Speed–distance–time: distance = speed × time; 72 km/h equals 20 m/s (divide km/h by 3.6).

Work rate adds reciprocally: if A finishes in 6 h and B in 3 h, together they do 1/6 + 1/3 = 1/2 of the job per hour, i.e. 2 h total.

Weighted average = Σ(value × weight) ÷ Σ(weights); use it for mixed postage rates or average handling times per parcel type.

Ratio scaling: keep units consistent before dividing; 1.5 t = 1,500 kg, 1 km = 1,000 m, 1 h = 3,600 s.

Rounding rule for money: compute unrounded, round only the final result; rounding intermediate steps can shift a cent-per-item total.

Compound growth over n periods: final = start × (1 + r)^n; doubling time ≈ 70 ÷ percentage growth rate.

Reverse percentages: if a price after 15% discount is 68.00, the original was 68 ÷ 0.85 = 80.00, not 68 × 1.15.

Only statements directly supported by the passage count as true; outside knowledge and plausible inference are marked 'cannot say'.

Scope words decide truth value: 'all', 'only', 'never', 'must' are falsified by a single counterexample in the text.

Distinguish fact from claim: a passage reporting that someone asserted X supports 'X was asserted', not 'X is true'.

Comparative statements require both items in the text; if one value is missing, the answer is 'cannot say'.

Watch quantifier shifts between stem and passage: 'most' ≠ 'all', 'some' ≠ 'many', 'may' ≠ 'will'.

Cause and correlation: a passage stating two events coincide does not license a causal answer.

Time markers (before, since, until, by 2020) fix sequence; an event described as planned is not described as completed.

Answer the question asked: elimination of options that are true but irrelevant to the stem saves time under pressure.

Check the four basic numeric series first: constant difference, constant ratio, alternating two-series, and differences of differences.

Interleaved series: split odd and even positions; each sub-series often follows its own simple rule.

Fibonacci-type rule: each term equals the sum (or sum minus one) of the two preceding terms.

Matrix puzzles: test movement rules separately - rotation (90°/180°), reflection, and element count change.

Rotation preserves shape and handedness; reflection reverses handedness - a mirrored arrow cannot be produced by rotation alone.

Syllogism validity: 'All A are B' plus 'Some B are C' yields no conclusion about A and C.

Negation test for assumptions: if denying the statement destroys the argument, the statement is a necessary assumption.

Element-count and position rules often alternate (add one, move clockwise, remove one); verify a rule against all given figures, not just the first two.

Compare character by character, not by word shape; transposed digits (6041 vs 6014) and doubled letters are the standard error types.

Check postal-code and house-number pairs against the source twice: once left to right, once right to left.

O/0, I/1/l, S/5, B/8, rn/m and cl/d are the highest-risk confusions in address strings.

Date format differs by locale: 03/04/2024 is 3 April in German usage and 4 March in US usage - confirm the convention.

In lists, scan for the requested attribute only; reading every field of every row burns the time budget.

Timed accuracy tasks: a wrong answer usually costs more than a skipped one; flag and return rather than guess.

Weight and dimension units must match before comparison; 1,200 g equals 1.2 kg, so 1,200 g is lighter than 1.5 kg.

Check digit logic: transposing two adjacent digits changes a mod-10 check result, which is exactly what such codes are designed to catch.

Priority order in complaints: safety and legal compliance first, then delivery outcome, then courtesy and explanation.

Acknowledge, clarify, act, confirm: the sequence that resolves a delivery complaint without escalation.

Never promise a delivery time or compensation you cannot verify; state what you will check and when you will report back.

When a customer is angry, separate the person from the problem: restate the concrete issue in neutral words before offering options.

Escalate when the request exceeds your authority (refunds, liability, data disclosure) or when the customer repeats a threat or legal claim.

Data protection: never confirm an address or shipment details to an unverified third party, including relatives.

Follow internal rules over customer preference when they conflict; explain the rule briefly and offer the permitted alternative.

Proactive service: report a known delay before the customer asks - it lowers complaint escalation more than apology after the fact.

Standard flow: acceptance → sorting hub → line haul → delivery depot → last mile → delivery or notification card.

Postage classes differ by weight, size and speed; a parcel exceeding a size limit is priced as a larger format regardless of weight.

Track-and-trace statuses are sequential; 'in transit' means handed to the network, not out for delivery.

Registered or signature-required items need proof of delivery; leaving them with a neighbour requires the recipient's consent.

Undeliverable items follow a retention period, then return to sender; the sender bears return costs unless otherwise agreed.

Hazardous and prohibited goods (lithium batteries, aerosols, perishables) are rejected at acceptance, not at the hub.

Address quality drives delivery success: street, house number, postal code and town must all be present and consistent.

Scan events are the audit trail; a missing final scan is the first thing to check in a 'not received' case.

German formal address uses 'Sie' with capitalisation in letters; 'du' is reserved for informal or agreed contexts.

German noun compounds take the gender of the last element: der Brief + der Kasten = der Briefkasten.

Formal German letter opening: 'Sehr geehrte Damen und Herren,'; closing: 'Mit freundlichen Grüßen' - no comma after the closing formula.

English false friends for German speakers: 'bekommen' = to receive (not become), 'eventuell' = possibly (not eventually), 'aktuell' = current.

German time and date: 'am 3. April', 'um 14:30 Uhr'; English: 'on 3 April', 'at 2:30 p.m.'.

Passive and impersonal forms suit formal notices: 'Die Sendung wird am nächsten Werktag zugestellt.'

Keep one register per text: mixing 'Sie' and 'du' in the same customer message is a style error, not a minor slip.

Numbers and units localise: German uses comma decimals (1,5 kg) and 'km/h'; English uses 1.5 kg.