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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.

752

Ready to practise

174

Not yet playable

926

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.

Practise Learnr’s own questions →Follow a role-specific curriculum →

752 matching entries · page 1 of 16

Math Questions · Medium

How Many Dogs

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 shelter contains 30 animals, all dogs or ducks. Every dog has four legs and every duck two, with no missing legs. There are 84 legs in total. How many dogs are there?

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.
→ 12

There are 12 dogs and 18 ducks.

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.