Computing
2 breaks
The ideas inside the machines we use all day.
AllBiologyComputingEarth & SpaceEconomicsEngineeringFood ScienceHistoryLanguageMathsMindMusic & SoundPhysics
Why swapping cards at random is not a fair shuffle: Fisher–Yates and the 27 paths
Shuffling three cards by swapping each one with a random card from the whole row looks fair, but it is not. It makes 3 × 3 × 3 = 27 equally likely paths for…
How one extra digit on your bank card catches your typos
The last digit of your bank card number isn't part of your account. It's a check digit, computed from the other fifteen by a recipe an IBM engineer patented in…