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Topic: 1000 light bulbs (Read 3167 times) |
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Weasel
Newbie
Posts: 1
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1000 light bulbs
« on: Mar 1st, 2003, 11:47am » |
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There are 1000 light bulbs all switched off.
Starting with number 1, going up to 1000 by jumps of one
(i.e. 1,2,3, etc.), you will turn ON each light bulb
that is off, and each light bulb that is on will be
turned OFF, then you start again going up this time by
jumps of two (i.e.2, 4,6,etc.) Start all over again with
jumps of 3(i.e.3, 6,9,etc.), jumps of 4,5,6 etc. until
you reach Jumps of 1000. Here is the question: how many
light bulbs will be left on by the time you reach jumps
of 1000? Remember on each jump you will turn ON each
light bulb that is off, and each light bulb that is on
will be turned OFF.
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Icarus
wu::riddles Moderator
Uberpuzzler
Boldly going where even angels fear to tread.
Gender: 
Posts: 4863
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Re: 1000 light bulbs
« Reply #1 on: Mar 1st, 2003, 8:58pm » |
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This is essentially the same puzzle as Circular Jail Cell, whose thread is here.
The only substantial difference is 1000 objects rather than 100. There are 31 lights left on at the end.
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"Pi goes on and on and on ...
And e is just as cursed.
I wonder: Which is larger
When their digits are reversed? " - Anonymous
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