Strawberries

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Sentzeu
Posts: 102
Joined: Sat Aug 21, 2004 12:16 am

Strawberries

Post by Sentzeu » Sun Aug 29, 2004 12:44 am

Consider a ring of N strawberries. A little girls starts at a strawberry eats it and then skips the second one and eats the third, skips the fourth and eats fifth and so on when she reaches the beginning she continues the same way as above, ignoring the new spaces between the strawberries.

The question now is, what number of strawberries in the interval 60<N<96 will it take so than when she is finished with her trips around the ring of strawberries, the last strawberry she eats is the one right behind the first one she starts with?

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ceptimus
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Post by ceptimus » Sun Aug 29, 2004 5:24 am

I'm taking a bit of a leap at this one, as I'm going out for the day, and only have five minutes, but here goes...<br><br><table><tr bgcolor="#c0c0e0"><td> Spoiler - 'select' text using mouse, or press Ctrl-A to reveal. </td></tr><tr bgcolor="white"><td><br>The initial number of strawberries can't be odd, or the girl will eat the target strawberry on her first circuit. Similarly, if the initial number were twice an odd number she would eat the target on her second pass. To keep the target strawberry till last of all, the initial number should therefore be a power of two, and the only power of two within your specified range is 64.<br><br></td></tr></table><br>

Sentzeu
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Joined: Sat Aug 21, 2004 12:16 am

Post by Sentzeu » Sun Aug 29, 2004 9:23 pm

Correct

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DanishDynamite
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Post by DanishDynamite » Mon Aug 30, 2004 8:07 pm

Hey Sentzeu, you seem to be getting your puzzles from the same place I do! :) Does Georg Mohr ring any bells?

Sentzeu
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Joined: Sat Aug 21, 2004 12:16 am

Post by Sentzeu » Mon Aug 30, 2004 8:17 pm

This one in particular I got from an old Georg Mohr task, when I posted this particular puzzle I was to tired to make anything by myself.

Have never participated in Georg Mohr, I get to nervous, but I like doing the tasks that they have on the archieve, since they give me a sense of challenge.

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DanishDynamite
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Post by DanishDynamite » Mon Aug 30, 2004 8:20 pm

Sentzeu wrote:This one in particular I got from an old Georg Mohr task, when I posted this particular puzzle I was to tired to make anything by myself.

Have never participated in Georg Mohr, I get to nervous, but I like doing the tasks that they have on the archieve, since they give me a sense of challenge.
Likewise. In any case I believe the Georg Mohr challenges are for kids in high school and I never attended high school in Denmark.

But they are great ways to keep the little grey cells active when taking the subway to and from work. :)