Combinatorics Interview Questions for Quant Developers
Quant Developers get asked combinatorics differently from other quant roles - the emphasis shifts with what the job actually does. This is that slice.
85 questions, all free to practise. The split is 24 easy, 32 medium, 29 hard.
- A divisor of a power of tenEasyProbabilityCombinatoricsView →
- A majority of onesEasyCombinatoricsView →
- A repeated digit in the PINEasyProbabilityCombinatoricsView →
- An even palindromeEasyProbabilityCombinatoricsView →
- An odd subset with two small elementsEasyCombinatoricsView →
- Arranging colored balls in a lineEasyCombinatoricsView →
- BALLOON arrangements bookended by vowelsEasyCombinatoricsView →
- Codes with exactly one vowelEasyCombinatoricsView →
- Counting 8-bit stringsEasyCombinatoricsView →
- Counting nines to 1000EasyCombinatoricsBrainteasersView →
- Counting up-down walks to a targetEasyCombinatoricsView →
- Distinct-digit numbers using a 7EasyCombinatoricsView →
- Divisible by 2 or 3EasyCombinatoricsView →
- Divisible by neither 2 nor 3EasyCombinatoricsView →
- Handshakes across two groupsEasyCombinatoricsView →
- Hopping rabbit, up to three stepsEasyProbabilityCombinatoricsView →
- Integers that contain a zeroEasyCombinatoricsBrainteasersView →
- Lattice paths through a checkpointEasyCombinatoricsView →
- MISSISSIPPI with the P's togetherEasyCombinatoricsView →
- Strictly increasing three-digit numbersEasyCombinatoricsView →
- Subsets containing one element but not anotherEasyCombinatoricsView →
- Three-one strings with matching endpointsEasyCombinatoricsView →
- Two ordering constraints at onceEasyProbabilityCombinatoricsView →
- Units digit of a random productEasyProbabilityCombinatoricsView →
- A family clustered at a round tableMediumCombinatoricsView →
- Anagrams of LOLLIPOPMediumCombinatoricsView →
- Balanced parenthesesMediumCombinatoricsProgramming & DSAView →
- Climbing stairsMediumCombinatoricsProgramming & DSAView →
- Deleting every other number on a circleMediumCombinatoricsBrainteasersView →
- Distinct die labelingsMediumCombinatoricsBrainteasersView →
- Last two digits of a powerMediumCombinatoricsBrainteasersView →
- Lattice paths in 3DMediumCombinatoricsView →
- Median of a list and its squaresMediumCombinatoricsStatisticsView →
- Monotone paths across a gridMediumCombinatoricsView →
- No two evens adjacentMediumCombinatoricsView →
- No two heads in a rowMediumProbabilityCombinatoricsView →
- No two neighboring bulbs litMediumProbabilityCombinatoricsView →
- Non-attacking rooksMediumCombinatoricsView →
- Odd multiples of threeMediumCombinatoricsBrainteasersView →
- Odd solutions to a sumMediumCombinatoricsView →
- One random subset inside anotherMediumProbabilityCombinatoricsView →
- Onto functionsMediumCombinatoricsView →
- Paths on a 4×3 gridMediumCombinatoricsView →
- Placing operators among digitsMediumCombinatoricsView →
- Regions from ten linesMediumCombinatoricsBrainteasersView →
- Spaced onesMediumCombinatoricsView →
- Sum of multinomial coefficientsMediumCombinatoricsView →
- Sum of the pandigital numbersMediumCombinatoricsBrainteasersView →
- Summing digits to a millionMediumCombinatoricsBrainteasersView →
- Ten dice, sum divisible by sixMediumProbabilityCombinatoricsView →
- Terms in a multinomial expansionMediumCombinatoricsView →
- The die that makes sums uniformMediumProbabilityCombinatoricsView →
- Three-four-five in Pascal's triangleMediumCombinatoricsBrainteasersView →
- Tiling a stripMediumCombinatoricsView →
- Trailing zeros of 100!MediumCombinatoricsView →
- Units digit of a random powerMediumProbabilityCombinatoricsView →
- A rectangle over the shaded rowHardProbabilityCombinatoricsView →
- A weighted sum of binomialsHardCombinatoricsBrainteasersView →
- Average of near-diagonal numbersHardCombinatoricsBrainteasersView →
- Balls into bowls, three eachHardCombinatoricsView →
- Dealing until kings or a king-and-aceHardCombinatoricsExpected ValueView →
- Digits with distinct pairwise sumsHardCombinatoricsBrainteasersView →
- Domino tilings of a 3×8 gridHardCombinatoricsView →
- Doors toggled by primesHardCombinatoricsBrainteasersView →
- Everyone gets one of eachHardProbabilityCombinatoricsView →
- Largest pairwise-coprime subset sumHardCombinatoricsBrainteasersView →
- Last one standingHardCombinatoricsBrainteasersView →
- Locks for a four-of-seven safeHardCombinatoricsBrainteasersView →
- 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 →
- Rotations divisible by 37HardCombinatoricsBrainteasersView →
- Seven seated in age orderHardProbabilityCombinatoricsView →
- Shuffles to restore the deckHardCombinatoricsBrainteasersView →
- Smallest number with digit product 10000HardCombinatoricsBrainteasersView →
- Subsets with one consecutive pairHardCombinatoricsView →
- Sum of repeating decimalsHardCombinatoricsBrainteasersView →
- Sums of fours and fivesHardCombinatoricsBrainteasersView →
- Ten prime digits with a set productHardCombinatoricsView →
- Three eggs, nine dropsHardCombinatoricsBrainteasersView →
- Triangle with equal side sumsHardCombinatoricsBrainteasersView →
- Two elements in the long cycleHardProbabilityCombinatoricsView →
- When k-to-the-k is a squareHardCombinatoricsBrainteasersView →
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