Where did the missing dollar go in this hotel riddle?

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Discussion Overview

The discussion revolves around a mathematical riddle involving a hotel scenario where three guests check in and experience a discrepancy in the accounting of their payments. The focus is on the reasoning behind the perceived "missing dollar" and the implications of how the payments are structured.

Discussion Character

  • Exploratory, Debate/contested, Mathematical reasoning

Main Points Raised

  • One participant outlines the riddle and the confusion surrounding the total payments made by the guests and the bellboy's actions.
  • Another participant clarifies that the total amount paid by the guests includes both the hotel room charge and the bellboy's tip, arguing that the $2 kept by the bellboy is already included in the $27 total.
  • This participant emphasizes that the accounting can be completed by adding the $3 returned to the guests to the $27, resulting in the original $30.
  • A later reply acknowledges the correctness of the previous clarification, indicating agreement with the accounting explanation.
  • Another participant notes the riddle's historical context and highlights two psychological points: the difficulty people have with fractions and the tendency to overlook hidden charges.

Areas of Agreement / Disagreement

While some participants agree on the resolution of the riddle, the discussion reflects differing perspectives on the reasoning behind the perceived missing dollar, indicating that multiple views remain on how the riddle is interpreted.

Contextual Notes

The discussion involves assumptions about how payments are perceived and the psychological factors influencing participants' understanding of the riddle, which may not be universally applicable.

Who May Find This Useful

Individuals interested in mathematical puzzles, cognitive psychology related to problem-solving, or those exploring common misconceptions in accounting scenarios may find this discussion useful.

Theelectricchild
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Math related riddle!

Three people check into a hotel. They pay $30 to the manager and go to their room. The manager suddenly remembers that the room rate is $25 and gives $5 to the bellboy to return to the people. On the way to the room the bellboy reasons that $5 would be difficult to share among three people so he pockets $2 and gives $1 to each person. Now each person paid $10 and got back $1. So they paid $9 each, totalling $27. The bellboy has $2, totalling $29. Where is the missing $1?

Good luck you'll need it!
 
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"Now each person paid $10 and got back $1. So they paid $9 each, totalling $27."

The people paid BOTH the hotel room bill AND (unknowingly) the bellboy $27 total ($25 + $2). $25 charged for the hotel room; $2 kept by bellboy

What isn't accounted for yet is the $3 the people got back.

"The bellboy has $2, totalling $29."

$2 was already accounted for in the $27. Why add it again?

"Where is the missing $1?"

Nothing is missing. Complete the accounting with $27 (hotel AND bellboy) + $3 (change from $30) = $30 (money originally paid by the people)

------

ADDITIONAL-

If you like it better:

per person: ($8+$1/3) share of room charge + ($2/3) secret bellboy tax + ($1) refunded = $10 originally paid amount
 
Last edited:
Yup you're correct!
 
It is an old puzzle. I haven't heard it for a long time. It illustrates two good points:

1. People are reluctant to deal with fractions, so they are easily distracted by exact integer amounts ($30 paid, $3 back).

2. People are easily overcharged when hidden surcharges are buried inside a payment and they are induced into paying them again.

Best of Luck!
 

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