Math Is Fun Forum

  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 2008-02-16 14:57:44

helloying
Member
Registered: 2008-02-16
Posts: 4

Where is the remainding $1

3 frens went to cafe.the bill was $75
Each gave $25
Waiter took it to counter.
The cashier decided to give them a dicount of $5 & asked waiter to return them $5
Now the waiter was confused, how to distribute $5 among 3 people?
He kept $2 in his pocket and gave $1 to each person.
So now each person actually paid $24 as they had taken one dollar back.
so $24 × 3=$72 and $2 in waiter pocket
It adds up to $74 but they had paid $75
Where is the remainding $1?

Offline

#2 2008-02-16 16:17:22

JohnnyReinB
Member
Registered: 2007-10-08
Posts: 453

Re: Where is the remainding $1

This is actually due to addition of the wrong figures. By discounting 5$, they actually pay approximately $23.33 each, for a total of $70. They get $3 back, making the total $73. Add the amount the waiter took, the total would be $75. Yey!!!!


"There is not a difference between an in-law and an outlaw, except maybe that an outlaw is wanted" wink

Nisi Quam Primum, Nequequam

Offline

#3 2008-02-16 16:52:17

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,711

Re: Where is the remainding $1


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Offline

#4 2008-02-17 00:56:40

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

Re: Where is the remainding $1

Elsewhere, the waiter's much greedier brother was working in a different restaurant.
By a remarkable coincidence, three friends went out to eat and their bill also came to $75. Each gave $25, as before.
The cashier had a crush on one of the people, and decided to refund $50 of their bill.
The waiter was confused - how to split $50 among 3 people?
He decided to give them $1 each and keep $47 for himself.

Now, each person paid $24, as they got $1 back, making $72 in total. The waiter has $47 in his pocket, so that adds up to $119.

yikes yikes So where did the extra $44 come from??? yikes yikes


Why did the vector cross the road?
It wanted to be normal.

Offline

#5 2008-02-17 01:42:02

JaneFairfax
Member
Registered: 2007-02-23
Posts: 6,868

Re: Where is the remainding $1


swearswear So where on earth does anyone get the idea of $119 from??? swearswear

Offline

#6 2008-02-17 02:47:34

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

Re: Where is the remainding $1

That's exactly the point.
I was stating the original puzzle with different numbers to make the discrepancy a lot bigger, to show why that way of thinking is clearly nonsense. The original one confuses people because there's only one missing dollar.


Why did the vector cross the road?
It wanted to be normal.

Offline

#7 2008-02-17 03:20:48

JaneFairfax
Member
Registered: 2007-02-23
Posts: 6,868

Re: Where is the remainding $1

Sometimes it’s better to expose the absurdity of a piece of choplogic reasoning by lucid mathematical demonstration than by inventing an even more absurd example based on the first. smile

Offline

#8 2008-02-17 08:17:45

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,711

Re: Where is the remainding $1

JaneFairfax wrote:

Sometimes it’s better to expose the absurdity of a piece of choplogic reasoning by lucid mathematical demonstration than by inventing an even more absurd example based on the first. smile

Oh now .... that is clearly absurd!


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Offline

Board footer

Powered by FluxBB