General Question

mea05key's avatar

Brain Teaser?

Asked by mea05key (1812points) January 23rd, 2009

Okay. I am bored so here’s an old brain teaser question for everyone.
3 guys went to the hotel to meet their girls. They met the receptionist who charged them 10 dollars per night for each person. They quickly settled their bills and head off to their rooms. Later the receptionist found out that the room rate was wrong. It was suppose to be 25 dollars for the 3 rooms. But this receptionist is tricky, so he took away 2 dollars for himself and return a dollar each to the 3 guests.
Now,

10dollars – 1 dollar =9 dollars , so each of the guests effectively paid 9 dollars for their rooms.
9 dollars times 3= 27 dollars, which is the total amount paid by the 3 guests for their rooms .

NOw, 27 dollars + 2 dollars ( stole by receptionist)=29 dollars, and where does the 1 dollar gone to since , initially the 3 rooms costs 30 dollars.

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12 Answers

arnbev959's avatar

This drove me crazy the first time I saw it, and it still bothers me.

90s_kid's avatar

THE DOLLAR BILL FELT ALONE, SO IT RAN AWAY.

El_Cadejo's avatar

well as you know pete, .999999999=1 :P

Snoopy's avatar

@mea05key honestly, the physics question you posted was enough of a brain teaser for me…
:)

arnbev959's avatar

that’s a completely different subject, uber.

El_Cadejo's avatar

yes, i know, i just like to bring it up when i can :P

DrBill's avatar

This is a classic deception question, the trick is to give you an invalid formula to get you thinking in the wrong direction, try it this way….

Each man paid $9 and got back $1 each, so 9+9+9+1+1+1=30

OR

Receptionist has $2, each guest has $1, room cost $25, so 2+1+1+1+25=30

Class dismissed.

Nimis's avatar

You should be subtracting the 2.00 in pocket
from the 27.00 (not adding) to get 25.00.

Hotel…Receptionist…Three Men
0…......0…................30
0…......30…..............0
30….....0…...............0
25….....5…...............0
25….....2…...............3

Nimis's avatar

@DrBill I agree with your assessment and your second statement:
Receptionist has $2, each guest has $1, room cost $25, so 2+1+1+1+25=30

But for some reason, the math works but your first statement bothers me.
Each man paid $9 and got back $1 each, so 9+9+9+1+1+1=30

Though I’m not exactly sure why!

LostInParadise's avatar

The key is to realize that the $2 comes from the $27, not added to it.

$25 – cost of room
$2 – kept by clerk
—————————- —- subtotal of $27
$3 – returned to men
——————————
$30

Nimis's avatar

Oh! I know what bothers
me about that statement.
It’s the order of events.

Each man paid $9 and got $1 each.
Sounds like (9–1)+(9–1)+(9–1)?

Each man got back $1 and ended up paying $9 each.

sndfreQ's avatar

I knew this one had been asked before but couldn’t find the link, but 90s_kid just answered it this morning (coincidentally-thanks though!), and it popped up in activity.

http://www.fluther.com/disc/15353/where-is-the-other-buck/#quip183703

Ahh..now I can go about my OCD happy way…

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