# Where is the 1 \$??

Discussion in 'Odds & Ends' started by billnepill, May 9, 2011.

1. ### billnepillHall of Fame

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(Inspired by the simple equation thread that is already 50+ pages, lol)

Suppose 3 people go to a restaurant. The bill is 30 \$. Each pays 10 \$. The manager notices they are regular customers and decides to give them 5 \$ back. The three take 1 \$ each and give 2 \$ tip to the waiter.

Because they take 1 \$ back, they in fact pay 9 \$ each, right?

But 9 + 9 + 9 equals 27 \$ + the tip of 2 \$ = 29 \$ total.

The bill was 30 \$. Where is the 1 \$??

2. ### mightyrickLegend

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1) Group eats. (Group=\$30, Manager=\$0, Waiter=\$0)
2) Group pays bill without any tip. (Group=\$0, Manager=\$30, Waiter=\$0)
3) Manager gives \$5 rebate to group. (Group=\$5, Manager=\$25, Waiter=\$0)
4) Group pays a small tip (\$2) to waiter. (Group=\$3, Manager=\$25, Waiter=\$2)

I'm not sure where the issue is.

At the end, the group has \$3. The manager has \$25. The waiter has \$2. \$30 total for all three.

3. ### ScoopsHaaganDazsRookie

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10 + 10 + 10 = 30
30 - 5 =25
25 + 2= 27
27 + 3 = 30

4. ### billnepillHall of Fame

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all in all, they each pay 9 \$ and give 2 \$ to the waiter =29 \$

5. ### snoflewisHall of Fame

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the 3 people giving \$2 for tip is inclusive in the \$9 that they each pay.
bill is \$30, manager gives \$5 back, which essentially makes the bill \$25 or \$8.33/person. They decide to give the waiter a \$2 tip in total, which comes out to \$0.67/person. so they each end up paying \$9.

6. ### MarrratSafinHall of Fame

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The way the question is laid out is misleading.
-They pay \$10 each, that's \$30 total. Put it in a pool on the table.
-The manager throw out \$5, that makes \$35 total in the pool.
-They take \$1 each, that means \$10 + \$1 = \$11 each. \$11 x 3 = \$33.
-Waiter takes \$2.
-\$33 + \$2 = \$35

Last edited: May 9, 2011
7. ### snoflewisHall of Fame

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there was only \$30 to begin with. when the manager gives them the money back, it comes from the \$30 that was paid, so it can't be \$35.
although, if you know how to make an additional \$5 appear from \$30, please shoot me an email haha.

8. ### billnepillHall of Fame

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But they first take the one dollar each and then hand out the tip. Taking the dollar made their individual bill 9 \$ already.

From their perspective they paid 9x3 + 2 = 29.

P.S. Your answer is correct. I tried to explain it once to a friend who never got it and said it is math failure lol...

Last edited: May 9, 2011
9. ### snoflewisHall of Fame

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haha. math never fails.
i, on the other hand, have failed math plenty of times. lol

10. ### sureshsBionic Poster

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Done before on this forum

11. ### billnepillHall of Fame

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man you are a member in this forum for more than a half a decade

Maybe non-ancient posters haven't seen it.

12. ### ClaudiusProfessional

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I'm just waiting for BreakPoint to say that the dollar is actually missing.

13. ### Legend of BorgLegend

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I thought this thread was about the latest controversy with Petros and his tipping habits.

Shame.

14. ### MarrratSafinHall of Fame

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Cool. 10 chars.

15. ### billnepillHall of Fame

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LMAO

Petros already solved this problem by not giving a tip. No tip = no headaches.

Wise man

16. ### baek57Professional

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That's a pretty skimpy tip, especially after getting \$5 back. \$2 is barely a 6.7% tip. Generally tipping is at least 15% which would've been \$4.50. They should've just left the \$5 for the waitress!

17. ### Squall LeonheartRookie

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I believe that this is one example of why we have the order of operations: if you do math in random order, errors can occur.

18. ### pinky42Rookie

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No, they chipped in \$27. The bill was \$25 leaving \$2. Instead of dividing the \$2 between themselves, they gave it to the waiter. 9x3 = 25 + 2. The error is adding the \$2. It is part of the \$27 that is split between the bill and the tip.

19. ### ProgressoRHall of Fame

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Its stuff like this why I dropped maths at 13. I saw this puzzle back around then and could not figure it out where the missing money went. Even when i saw a so called solution, it made no sense. Maths is very dangerous, it makes money disappear and if you do not understand it its best to stay away from it. I used to stress and lose whole night's sleep about how Maths was supposed to make sense but instead it turned the world upside down.

That is why I pay by credit card.

20. ### DilettanteHall of Fame

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I have a better question:

Where are the Enron and Lehman Bros' dollars?

You guys with all the maths and stuff are not smart enough to answer this.

Last edited: May 10, 2011
21. ### mucatHall of Fame

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30

30-5= 25

25+3=28

28 +2= 30