[kylewins]

Rough Calculation:

11.7 billion one dollar bills are in circulation today

100,000 / 11,700,000,000

Every Day 1 in Million Chance of Winning

The guy was seemingly clever why not take the 5mins to find the odds or a few hours to ask the local math teacher...

[hh3k0]

Yeah, I'd wager it was his laziness and proneness to shortcuts. One thing, though: Article states the radio show took place a few months after he won so probably 1984 or 1985. Federal Reserve website states that there were 7.5 billion one-dollar bills in circulation in 1999 (couldn't find numbers for years prior 1999). Increase of one-dollar bills in circulation seems to have fluctuated a lot over the course of years, might have been a significantly lower number in 1984/1985. I mean, it'd still be an impossibly long shot but I felt like pointing it out.

[kylewins]

I was also thinking if the radio host was reading serial numbers from a specific newish year and the bank notes are more likely to be new then old maybe that would also increase the odds.

Yeah, but I'll pass on that. Give me a job at walmart over reading serial numbers all day.

Myth of sisphus

[mywittyname]

Depending on how the serial number was chosen, the odds could be dramatically higher, dramatically lower, or zero. If the serial number was derived from another, new bill, received from a local bank, then the odds are quite good.

If it is chosen by writing the serial number of a bill in your pocket, then circulating the bill by purchasing something. The odds go up if you happen to stop by the banks a few days after that happened, or they go to zero if the bill was not fit for circulation and it was removed by the Federal Reserve.

Also, there's a good chance that a random serial number is not actually valid.