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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

Math Questions · Medium

River Length #1

Original interpretation · Match confidence: medium

Company use unverified
About this question’s source match

Title plus Math Questions / General supports the stated family or explicit original interpretation; each source’s scope is limited below. The private title does not specify all mechanics. This independently designed title-specific scenario is not a recovered private question.

Original Learnr interpretation; the private catalogue statement is unverified. A boat moves at 10 km/h relative to still water. On a river with constant current it takes 2 hours to traverse a fixed reach downstream and 3 hours upstream. Find the reach’s length in kilometres and the current speed. Ignore turn-around time.

Assumptions and constraints

  • All measurements, permissions and rules in the statement are exact.
  • No unstated constraints apply.
  • Solve the fixed instance and justify the construction or calculation.

Examples

The scenario stated in the question.
→ {
  "length": 24,
  "current": 2
}

The reach is 24 km long and the current is 2 km/h.

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.