Combinatorics Questions for Systematic & Data-Driven Trading Interviews
A systematic & data-driven trading round does not test combinatorics the way a textbook does. This set is the overlap - the combinatorics questions that actually turn up in this format.
57 questions, all free to practise. The split is 9 easy, 18 medium, 30 hard.
- A coin that branches into a dieEasyCombinatoricsExpected ValueView →
- All the squares on a chessboardEasyCombinatoricsBrainteasersView →
- An even palindromeEasyProbabilityCombinatoricsView →
- Even numbers, distinct digitsEasyCombinatoricsView →
- Even-size, non-empty subsetEasyProbabilityCombinatoricsView →
- MISSISSIPPI with the P's togetherEasyCombinatoricsView →
- Strictly increasing three-digit numbersEasyCombinatoricsView →
- Three-one strings with matching endpointsEasyCombinatoricsView →
- Two ordering constraints at onceEasyProbabilityCombinatoricsView →
- A relay team with a feudMediumCombinatoricsView →
- Balanced parenthesesMediumCombinatoricsProgramming & DSAView →
- Boy–girl neighbors in a lineMediumCombinatoricsExpected ValueView →
- Deleting every other number on a circleMediumCombinatoricsBrainteasersView →
- Derangements of four itemsMediumCombinatoricsView →
- Distinct faces in five rollsMediumCombinatoricsExpected ValueView →
- Expected ascents in a shuffleMediumCombinatoricsExpected ValueView →
- Median of a list and its squaresMediumCombinatoricsStatisticsView →
- No two neighboring bulbs litMediumProbabilityCombinatoricsView →
- Non-attacking rooksMediumCombinatoricsView →
- Onto functionsMediumCombinatoricsView →
- Power of three in a factorialMediumCombinatoricsView →
- Squares on a chessboard, tilted ones includedMediumCombinatoricsBrainteasersView →
- Subsets with no neighborsMediumCombinatoricsView →
- Sum of the pandigital numbersMediumCombinatoricsBrainteasersView →
- The same number of tailsMediumProbabilityCombinatoricsView →
- Trailing zeros of 100!MediumCombinatoricsView →
- Variance of hearts in eight cardsMediumCombinatoricsStatisticsView →
- A rectangle over the shaded rowHardProbabilityCombinatoricsView →
- A weighted sum of binomialsHardCombinatoricsBrainteasersView →
- Ages from product and sumHardCombinatoricsBrainteasersView →
- Average of near-diagonal numbersHardCombinatoricsBrainteasersView →
- Cycles in a shuffleHardCombinatoricsExpected ValueView →
- Digits with distinct pairwise sumsHardCombinatoricsBrainteasersView →
- Doors toggled by primesHardCombinatoricsBrainteasersView →
- Expected largest of ten ballsHardCombinatoricsExpected ValueView →
- Handshakes at a dinner partyHardCombinatoricsBrainteasersView →
- Head density with no two in a rowHardProbabilityCombinatoricsView →
- Last one standingHardCombinatoricsBrainteasersView →
- Locks for a four-of-seven safeHardCombinatoricsBrainteasersView →
- Long cycles in a random permutationHardCombinatoricsExpected ValueView →
- Making change in lineHardCombinatoricsStochastic ProcessesView →
- No two samples too closeHardProbabilityCombinatoricsView →
- Odd sums on a 3×3 gridHardProbabilityCombinatoricsView →
- Only seven left unchosenHardProbabilityCombinatoricsView →
- Pairing gloves within oneHardProbabilityCombinatoricsView →
- Pairing with a difference of 1 or 11HardCombinatoricsBrainteasersView →
- Runs of red and blue marblesHardCombinatoricsExpected ValueView →
- Shuffles to restore the deckHardCombinatoricsBrainteasersView →
- Subsets with one consecutive pairHardCombinatoricsView →
- Sum of repeating decimalsHardCombinatoricsBrainteasersView →
- Ten prime digits with a set productHardCombinatoricsView →
- Three eggs, nine dropsHardCombinatoricsBrainteasersView →
- Two coprime integersHardProbabilityCombinatoricsView →
- Two elements in the long cycleHardProbabilityCombinatoricsView →
- Two walks returning togetherHardProbabilityCombinatoricsView →
- Two-color necklacesHardCombinatoricsView →
- When k-to-the-k is a squareHardCombinatoricsBrainteasersView →
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