Math Question... Let's go engineers!

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Airborneguy

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One of my co-workers is trying to create an interesting office pool. Here's the question:

What is the longest this could go on for?

The scenario is 10 people, each gets assigned a number from 0-9. Every day, when the evening lotto numbers are chosen, everyone who's number comes up (3 numbers are picked every night), gets a check. The first person to 25 checks wins the pot. If more than one of your number shows up, you get multiple checks.

Anyone? Did I explain it well enough?
 

DeafSmith

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OK, assuming that I understand the problem (not sure I do), the pool could at most last 81 days. Assume numbers 0, 1, and 2 are drawn the first day, 3, 4, and 5 the second, 6, 7, and 8 the third, 9, 0, and 1 the fourth, 2, 3, and 4 the fifth, etc., then after 10 days, everyone has 3 checks. After 80 days, everyone has 24 checks, so on day 81 someone must get to 25.
 
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Airborneguy

Airborneguy

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You understood, thank you. I think that's it. One of the guys actually came up with 80 days earlier, but I think he forgot to add the 25th check.

On a side note, I said it would take 15 minutes to get an answer here. It took 21. Not bad! Thanks again.
 

peaktopview

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If I had seen your post immediately you would have had your answer in 5 minutes (I'm a slow typist). :D
says the guy with the slide rule as his avatar. you used that to figure it out, didn't ya?

my dad's favorite scene from the movie "apollo 13" is when they all whip out the slide rules. he is a gmi grad(flint, mi) if that tells you anything. not sure of the exact year he graduated, late 60's, early 70's. still has his slide rules in the basement. i am not quite that old, calculators were around growing up. dad tried to show me a couple of times how to use one. didn't take.

b
 

weirdboy

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You don't have to translate Japanese for me, my friend. Also, 27? That's kind of insane. One of my friends in college, her father was a soroban teacher. She could just picture one in her head and do any calculation in like 3 seconds. It was uncanny.
 

DeafSmith

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You don't have to translate Japanese for me, my friend. Also, 27? That's kind of insane. One of my friends in college, her father was a soroban teacher. She could just picture one in her head and do any calculation in like 3 seconds. It was uncanny.
It's really amazing what people can do when they start learning something at a very young age. I was already about 60 before I started with the soroban so I am not very fast, but I enjoy playing with it anyway. I have gotten to the point where I can balance my checkbook as fast with the soroban as I can with a calculator, but I'll never be near as fast as the kids that start learning young. And I've never even attempted the mental calculations (anzan).
 

weirdboy

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Do you speak Japanese, or do you just know the words associated with soroban?

That particular word (暗算) has some interesting alternate meanings in Japanese.

I am an amateur at soroban, personally. That girl became an accountant after graduating.

:)
 

DeafSmith

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Do you speak Japanese, or do you just know the words associated with soroban?

That particular word (暗算) has some interesting alternate meanings in Japanese.

I am an amateur at soroban, personally. That girl became an accountant after graduating.

:)
I think with "soroban" and "anzan" I have used up all my Japanese vocabulary. I assume that you do speak Japanese?
 

weirdboy

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I think with "soroban" and "anzan" I have used up all my Japanese vocabulary. I assume that you do speak Japanese?
Yes, although not nearly as well as I used to. I still use it regularly, but most of my usage nowadays is limited to what to eat for dinner, etc. I still help out with some translation every now and then. At the very least, my grammar is still very good. :fro:
 

DeafSmith

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weirdboy

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If you are interested in soroban, there is a Yahoo group (mail list) here:

http://groups.yahoo.com/group/SorobanAbacus/

where we discuss soroban and suan pan and sometimes anzan.

There is also a files section there with some interesting stuff.


The list owner of that group has a web site here:

http://webhome.idirect.com/~totton/abacus/

and here:

http://webhome.idirect.com/~totton/soroban/


Cool! One of the things that I thought about while I was in college was trying to adapt boolean algebra to a soroban. There is a particular type of evaluation method for boolean algebraic expressions called Karnaugh maps that I always thought could be adapted to them, but never really got around to working out the details.
 

DeafSmith

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Cool! One of the things that I thought about while I was in college was trying to adapt boolean algebra to a soroban. There is a particular type of evaluation method for boolean algebraic expressions called Karnaugh maps that I always thought could be adapted to them, but never really got around to working out the details.
I used to use Karnaugh maps many years ago to design logic circuits. I never thought about using a soroban for Boolean algebra, but I did write a couple of papers for the Yahoo soroban/abacus group files section on multiplication and division in binary and decimal/binary conversion. I also wrote up papers on using the soroban with a slide rule and with a set of Napier's bones. I like to do "outside the box" stuff like that - it's a lot more fun than hours of practice trying to become fast at using the soroban.
 
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