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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

Brain Teasers · Easy

Weighing Blocks

Original interpretation · Match confidence: medium

Company use unverified
About this question’s source match

Title plus Brain Teasers / Logical 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. Among27 externally identical blocks exactly one is heavier than every other block; all normal blocks have equal weight. An ideal balance scale has three outcomes and compares equal-sized groups. Find the minimum worst-case weighings to identify the heavy block.

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.
→ 3

Exactly3 weighings are necessary and sufficient.

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.