10 Questions to Find a Number (August 2025 Challenge Question)

Well, Rixter, I guess it is ‘Game Over’ when you hit a home run on the first pitch of the game.

Well done!

Thanks.

Uh oh… I just noticed an error in #1.

Step 8: 104 minus 4 does not equal 102.

It still works with the value reset.

Sorry.

But your logic falls apart if the denomination is a coin.

Let's all try again!

Is it $500?

Is it $100?

Is it $50?

Is it $20?

Is it $10?

Is it $5?

Is it $2?

Is it $1?

Ya still have two more guesses.

My first two questions would be:

1) Is the denomination currently in circulation?

2) Is the denomination paper?

You now have eight remaining questions.

Perhaps DALE will gift you his unused questions.

I've put my solution on paper.

So far I've narrowed it down to a maximum of six questions to determine the denomination.

I'll post the logic diagram before too long.

This was a fun challenge because it required me to find out how many denominations of currency the US has used over the years. It turned out to be much more than I expected it to be.

To answer which denomination was in the person's pocket then basically became a process of elimination.

To start: The denomination could be paper or coin. And it could be currently in circulation or not. And some past coins were actually made of gold.

The logic flow diagram begins to sort them as paper or coin, in circulation or not, and gold coin or not.

If a denomination is paper and in circulation, another 3 questions max to narrow it down.

If a denomination is paper and not in circulation, another 3 questions max to narrow it down.

If a denomination is coin and in circulation, another 3 questions max to narrow it down.

If a denomination is a gold coin (and obviously not in circulation), another 3 questions max to narrow it down.

If a denomination is a coin (other than gold and not in circulation), another 3 questions max to narrow it down.

So, six questions max to determine the denomination.

I’m throwing you a GA on this. While I’m not a numismatic expert, I cannot think of another US denomination you haven’t covered.

The question does say denomination, not some amount of paper money. This is my read error. The binary chop in #1 is exactly ten steps to determine any face value amount of US paper money in circulation that you might have in your wallet, up to USD$1,024.00

However, your solution also assumes at least one fact not in evidence: United States monies. Several other global monetary systems use the dollar sign.

There is sort of a hole in the question. Your solution still deserves a GA, I think. Well done!