Birthday paradox bites FEMA
Via the SacBee:
WASHINGTON (AP) – FEMA will replace locks on as many as 118,000 trailers used by Gulf Coast hurricane victims after discovering the same key could open many of the mobile homes.
One locksmith cut only 50 different kinds of keys for the trailers sold to FEMA, officials said Monday
The article continues:
That means, in an example of a worst-case scenario, one key could be used to unlock up to 10 mobile homes in a park of 500 trailers.
Uh, no. Actually, worst-case would be one key opens every trailer. Ten is the expected value (assuming randomly distributed locks)
There’s already a single “key” that opens every trailer door. It’s called a hammer. It isn’t clear to me that replacing these lock cylinders is a smart way to spend money.
Would it be unreasonable to ask the users of these trailers to foot the bill for the new lock cylinders themselves? Seems that making this a FEMA-managed task will increase the total cost, and probably delay the fix.
What do others think?