Safe Speed Forums

post totally edited:

I think I was slightly wrong before. I think the reduction is "the probability that the sum of the two smallest numbers (of three) are greater or equal to the largest one".
So 0.5!

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

It's the same thing. Assuming you start by cutting the rod into two pieces (unless you make both cuts simultaneously, but the principle remains the same)
you now have two pieces. You then cut one of them into two. If you cut the longer of the two pieces then you can make a triangle, but if you cut the shorter of the two then you can't.

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Only when ideology, prejudice and dogma are set aside does the truth emerge - Kepler

Be careful! Both cuts of the original rod were independent.

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http://kalvis.com/

You probably didn't see that I edited that post (before you submitted yours) as I realised what I said within it wasn't relevant. I have given my new answer within it (and we seem to be in agreement with the final figure ).

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

oh, oops!. The probability must be less than 0.5, because, even if you cut the longer of the two pieces you can still end up with one piece longer than the sum of the other two. I'll work it out.

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Only when ideology, prejudice and dogma are set aside does the truth emerge - Kepler

It must be 0.25

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Only when ideology, prejudice and dogma are set aside does the truth emerge - Kepler

Ah, crap, yes, I did did a spreadsheet to prove my thoughts but I proved myself wrong. Lo and behold I again end up as the same answer as Pete (0.25, but I don't quite know why). Ho hum!

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

Prob = 1/4, is what I recall from a long time back, so I am glad that is what you are getting.

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http://kalvis.com/

If we can include riddles, here's one which surprisingly catches a few people out for a short time..

I am behind you but you are also behind me. How can that be?

No need to reply but try it on a few friends you know and see the look on their face as they look pensive for a while or even come up with some remarkable answers

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The views expressed in this post are personal opinions and do not necessarily represent the views of Safe Speed.
You will be branded a threat to society by going over a speed limit where it is safe to do so, and suffer the consequences of your actions in a way criminals do not, more so than someone who is a real threat to our society.

Ah yes, reminds me of that old story about a driver who stopped to ask a farmer how far it is to the village which he'd (unknowingly) just passed through

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Only when ideology, prejudice and dogma are set aside does the truth emerge - Kepler

Yep. I modelled it and get 0.25. But can't understand it intuitively

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When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
When I see a youth in a motor car I do d.c.brown

I would be nice to find a method that makes it look obvious, though it might not exist.

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http://kalvis.com/

An alien measures my height in alien units, and I have no idea what these units are. In normal scientific decimal notation, what is the probability that my height starts with a 1, in these alien units?

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http://kalvis.com/

I was just about to ask how many fingers the aliens had, then I saw you said "decimal"

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Only when ideology, prejudice and dogma are set aside does the truth emerge - Kepler

I make it 1/9

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Only when ideology, prejudice and dogma are set aside does the truth emerge - Kepler

Wrong!

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http://kalvis.com/

So do I
In 0-9 there is 1: 1/10 = .1
In 10-99 there are 10: 10+1/100 = .11
In 100 -999 there are 100: 100+10+1/1000 = .111
In 1000-9999 there are 1000: 1000+100+10+1/10000 = .1111

Convergent on .1 recurring or 1/9

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When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
When I see a youth in a motor car I do d.c.brown

That's what I like about (us) engineers; we can still find a way to get the right answer even when normal methods are beyond us

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

1/10

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My views do not represent Safespeed but those of a driver who has driven for 39 yrs, in all conditions, at all times of the day & night on every type of road and covered well over a million miles, so knows a bit about what makes for safety on the road,what is really dangerous and needs to be observed when driving and quite frankly, the speedo is way down on my list of things to observe to negotiate Britain's roads safely, but I don't expect some fool who sits behind a desk all day to appreciate that.

Wrong!

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http://kalvis.com/