A keyhole unlocks when a specific combination is inserted (usually represented by numbers, but we will use letters). Key A is xxxAx, Key B is xxxBx, and Key C is xxxCx. Keyhole A is configured to accept xxxAx and xxxCx. Keyhole B is configured to accept xxxBx and xxxCx. Here is a video that explains it and provides good visuals [https://youtu.be/8U6rdI_uG2c](https://youtu.be/8U6rdI_uG2c)
If you find this interesting, try watching more lockpicking videos, there are even more interesting things lock makers do 😃
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