This is a
cleverly-disguised case of subtracting
apples from oranges.
It's obvious that no dollar disappeared, and misleading to demonstrate that $27 + 2 = $29.
Here's a couple of ways to make this more clear:
- There was originally $30 in the world. Now the men each have $1, the manager has $25, and the clerk has $2. 3 + 25 + 2 = 30.
- Consider that the men each paid $9 (net). Then there's $27 dollars in the hotel: $25 in the manager's cash register and $2 in the sneaky clerk's pocket.
It all adds up.