| Title: | Mathematics at DEC |
| Moderator: | RUSURE::EDP |
| Created: | Mon Feb 03 1986 |
| Last Modified: | Fri Jun 06 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 2083 |
| Total number of notes: | 14613 |
PERHAPS THIS MAY PROVE TIRESOME FOR THE
TRUE MATH ATHLETES IN THE CROWD
BUT THE FOLLOWING NUMBER PROBLEM CAUSED SOME
FRUSTRATION AMONG A FEW OF US HERE. I THOUGHT
I'D SHARE IT
GOES LIKE THIS:
ROY AND BOB WENT TO A STORE TO GET A KEG OF BEER.
THE KEG COSTS $50.
(NO DEPOSITS REQUIRED AT THIS STORE)
THEY EACH PAID $25 TO SPLIT COST ON THE BEER.
THEY WERE OUTSIDE GETTING INTO THEIR TRUCK
THE STORE KEEPER HAD A SALE ON THAT PARTICULAR
BEER THAT DAY AND HAD OVER CHARGED THEM $5.
THE STORE KEEPER GAVE THE $5 TO AN ERRAND BOY
TO GIVE BACK TO BOB AND ROY.
THE KID DECIDES TO STEAL $2 FOR HIMSELF.
SO HE GIVES BOB AND ROY $1.50 EACH.
(THEY DON'T KNOW ANY BETTER)
WELL...
SINCE THEY GOT $1.50
BACK THAT MEANS THEY SPENT
23.50 EACH. RIGHT?
THAT'S $47 SPENT IN MY BOOK.
THE KID STOLE $2
THAT'S $49 IN ALL (I DID ADD CORRECTLY DIDN'T I?)
WHERE'S THE OTHER DOLLAR?
$23.50 ROY
$23.50 BOB
$2.OO ERRAND BOY STOLE
--------
$49.00 TOTAL
WHERE DID IT GO????
HAVE A GOOD DAY GENTLEMEN.
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 785.1 | It didn't go anywhere! | ZFC::DERAMO | Daniel V. D'Eramo | Sun Nov 08 1987 19:56 | 37 |
Network analysis follows:
|-----|<----- $ 1.50 <----- <----- <----- <----- <----- <----- <--|
| Bob | |
|-----|-----> $25.00 ----->|--------------| |-----|
| store keeper |-----> $ 5.00 ----->| kid |
|-----|-----> $25.00 ----->|--------------| |-----|
| Roy | |
|-----|<----- $ 1.50 <----- <----- <----- <----- <----- <----- <--|
Net flow from Bob $ +23.50
Net flow from Roy $ +23.50
Net flow from store keeper $ -45.00
Net flow from kid $ - 2.00
--------------------------------------
Total $ 0.00
Kirkoff's law is upheld! Money is neither created nor
destroyed! :^)
The problem was that you changed the sign of the kid's
"contribution" when you were totalling things up. You had
minus signs in front of the $1.50's -- that's why you went
from $25.00 to $23.50 instead of $26.50. So why ignore the
sign on the $2.00?
Or to look at it another way:
Net decreases: Bob $23.50 Net increases: kid $ 2.00
Roy $23.50 sk $45.00
---------- ----------
$47.00 $47.00
The "ledgers" do balance.
Dan
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| 785.2 | bellboy's younger brother | VINO::JMUNZER | Mon Nov 09 1987 09:31 | 3 | |
The extra money is in a hotel room (see note # 196.)
John
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