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Cross the 3 Couples

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Let A, B & C be the respective husbands of X, Y & Z.

Rules:

1. You need to take all 6 to the other side of the river along with the boat.

2. Atmost two can be on the boat at a time.

3. A wife cannot remain in the presence of a man(excluding her husband) at any side, except in that her own husband is with her i.e. AXB is possible, but XB is not.

4. All know boating.

Reply in steps. Use the same variables.

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Posted · Report post

Bit of trial and error at first, but pretty sure I got there.

post-1598-1187957510_thumbjpg

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Posted · Report post

1. You need to take all 6 to the other side ...

Please clarify - As you take them across the river, there can be no more than one of them with you in the boat?

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Posted · Report post

You can't do it taking one at a time, and taking them two at a time is trivial. So I'll answer the problem of how they do it themselves. [edit - one of my letters was wrong]

    xy cross, x returns --- .. .y .. || Ax B. Cz

      Ax cross, A returns -- .x .y .. || A. B. Cz

        Cz cross, C returns -- .x .y .z || A. B. C.

        AB cross, z returns - Ax By .. || .. .. Cz

          Cz cross ------------- Ax By Cz || .. .. ..

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Posted · Report post

That will work bonanova, except that at some points a wife is in presence of a man that isn't her husband.

Eg. at step 2, "Ax cross, A returns -- .x .y .. || A. B. Cz", y is in the presence of A on the same side as x is getting out of the boat.

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Posted · Report post

That will work bonanova, except that at some points a wife is in presence of a man that isn't her husband.
Your solution avoids that situation.

I think you solved a more difficult problem than was proposed.

I opted for my approach because

[1] It takes one fewer crossing

[2] I believe the conditions provide for a momentary situation where a woman is without her husband but with another man, so long as she does not remain that way when the boat leaves them.

Maybe the author can resolve whether my interpretation is permitted.

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Posted · Report post

@ tanric

Well done! This is the only right solution as far as I know.

@ bonanova

Your interpretation is wrong. Your second step i.e. (Ax cross, A returns -- .x .y .. || A. B. Cz) is wrong because if A crosses and finds another woman, he won't want to return, would he??? .

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Posted · Report post

i hope these couples are on their way to counseling.

damn wheres the trust??

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Posted · Report post

i hope these couples are on their way to counseling.

damn wheres the trust??

You mean we have to take a counselor across, too?

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Posted · Report post

And everyone knows counselors can only be in the boat with X or Y or C, and they can NOT row the boat. DUH!

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