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Interview practice

Solve complete questions with progressive hints, worked solutions and Python implementations. Each question explains its assumptions and source match. Original interpretations are labelled explicitly.

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Catalogue titles

Public standard problems and original exercises; hidden Trading Interview questions have not been verified.

174 titles have been investigated but remain unresolved. Their missing details are recorded without adding substitute exercises. Every playable question has a guided animated answer; selected questions also have custom diagrams.

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752 matching entries · page 1 of 16

Probability and Statistics · Easy

Fake News

Original interpretation · Match confidence: medium

Company use unverified
About this question’s source match

The title and category identify this topic, but do not reveal the private statement. The explicitly specified scenario is an original, title-specific interpretation. Exact Trading Interview wording, numbers and requested subparts remain unverified; this is not claimed to be the hidden source question.

In a fictional news stream, 10% of claims are false. A flagger flags 80% of false claims and 5% of true claims. For a random flagged claim, find probability it is false. Also find the false-claim probability for an unflagged claim.

Assumptions and constraints

  • Use the random mechanism explicitly specified in the prompt.
  • Give exact expressions where possible and justify each requested result.

Examples

1000 hypothetical claims
→ 80 false and 45 true claims flagged in expectation

Among the expected 125 flags, 80 concern false claims.

Company evidence · unverified

No company-specific source has been matched to this exercise. Its references support the topic or solution method; they do not establish employer use.

References

Read the supporting material without leaving your question.

Catalogue metadata captured 2026-10-12. Metadata source.