Fuzzy Math

[Jennifer]

A man walks into a store and buys a pack of gum that costs 75 cents with a 5 dollar bill, and the cashier hands him back $4.25.  Before the register closes, the man offers the cashier 5 singles in exchange for his 5 dollar bill back.  When the cashier agrees, the man slips him 4 one dollar bills and 1 five dollar bill, while taking back his original five dollar bill.  When the cashier alerts him to the mistake, the man acts surprised and says, “I’ll add one more dollar to make an even ten dollars and you can give me back a ten dollar bill.”  The  cashier agrees and the man walks out of the store five dollars richer.

How is this true?

[Baghdaddy]

@Jennifer:

A man walks into a store and buys a pack of gum that costs 75 cents with a 5 dollar bill, and the cashier hands him back $4.25.

Gum has nothing to do with the exchange, balance is 0

@Jennifer:

  Before the register closes, the man offers the cashier 5 singles in exchange for his 5 dollar bill back.  When the cashier agrees, the man slips him 4 one dollar bills and 1 five dollar bill,

Cashier now is + $9

@Jennifer:

while taking back his original five dollar bill.Â

Cashier now is + $4

@Jennifer:

When the cashier alerts him to the mistake, the man acts surprised and says, "I’ll add one more dollar to make an even ten dollarsÂ

Cashier is now +$5

@Jennifer:

and you can give me back a ten dollar bill."Â

Cashier is now - $5

@Jennifer:

The  cashier agrees and the man walks out of the store five dollars richer.

How is this true?

Cashier was educated by politicians?

[rjclayton]

Good job with the T-account Baghdaddy.  Political commentary might be more at home in another forum…

[ajgundam5]

I’m gonna have to try this sometime

[Baghdaddy]

@rjclayton:

Good job with the T-account Baghdaddy.  Political commentary might be more at home in another forum…

OK.  I changed it to a generic “politicians”.  More accurate in todays political/fiscal world anyway.

[Jennifer]

Good job, Baghdaddy.  No offense, but I’m actually surprised anyone on the board could solve it without a hint. :P  No offense, but it requres logic and thought and too many people don’t use either when trying to solve word problems.

[Baghdaddy]

@Jennifer:

Good job, Baghdaddy.  No offense, but I’m actually surprised anyone on the board could solve it without a hint. :P  No offense, but it requres logic and thought and too many people don’t use either when trying to solve word problems.

Engineering is a word problem.

Every project I have ever worked on started out as a problem description.  More often than not, the problem did not have enough information to determine if it was even solvable, much less what the solution was.

Classic example was “Make sure the USS Stark does not happen again.”

That particular problem ate up a good 10 years of my life, 20+ years of my fathers life and countless man-years of many people whom I know or met in the course of the project. http://www.fas.org/man/dod-101/sys/ship/weaps/outlaw_bandit.htm

The hard problems are the ones where you know you don’t have enough information to make a logical decision but the sooner you make the right decision, the more likely it is that you will win and the other guy won’t.  That is the real battlefield.

[Guest]

The smart ass in me wants to point out that the REAL answer to the Philladelphia Experiment was apparently putting a rubber on the ship!  LOL

[Jennifer]

Yes, Science, Engineering (which is kinda a hybred between science and math in my mind) and Pure Math (as in beyond algebra) are all word problems.

I have a tendancy to poke fun at Engineering students and Engineers because they are so easy to rile up.  But at least they have an honest profession.  They build things and help people - unlike some professions like Lawyers, Judges and Politicians, to name a few.