Kinesys lands, gently for once, in front of a Paradoxon establishment that, depending on how you look at it, seems to be a bar, a library, or a cave. Inside, luckily, it’s a bar.
Liz decides that, after yet another botched teleport, a round of drinks is mandatory. M00N is thrilled: “I’ll pay my share! I’ve got the savings from my piggy bank!” Dord orders a water at exactly room temperature, and checks the temperature twice.
Oddly enough, even on Paradoxon they pay in dollars, which Dord finds deeply suspicious. But it’s on the way out, when the three of them start doing the math, that the real paradox pops up, and Dord begins to seriously fear for his sanity.
The Riddle
After a round of drinks together, Liz, Dord, and M00N ask the waiter for the check, and he promptly brings the bill: the total comes to $30. Each of the three pulls out a $10 bill and hands it to the waiter, while grumbling that the check is rather steep. So they ask the waiter to go to his boss and get them a small discount.
The waiter tells the manager, who agrees and knocks $5 off the bill. The waiter then takes five $1 bills from the register and brings them back to the three friends, who decide to take back $1 each and leave the remaining $2 to the waiter as a tip, to thank him for his help.
Once outside, the three start doing the math: each of them effectively spent $9, for a total of $27; add the $2 left for the waiter and you get $29. But where did the missing dollar go, the one needed to get back to the original $30?
Hint
The “27 + 2” calculation adds up two things that shouldn’t be added together. Follow the original $30 instead: in the end, who has it?
Solution
The missing dollar didn’t go anywhere: the puzzle is built specifically to trick whoever tries to solve it.
The mistake is adding the $2 tip to the $27, when the tip is already included in the $27. The $27 the three paid altogether breaks down like this: $25 to the bar (the discounted check) and $2 as a tip for the waiter.
The correct accounting, starting from the original $30, is: $25 to the bar + $2 to the waiter + $3 returned to the three friends = $30. No dollar has vanished, not even on Paradoxon. Dord lets out a long, relieved sigh.