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# Cannibals and Missionaries

77 replies to this topic

### #61 rookie1ja

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Posted 09 November 2008 - 11:11 PM

Now let me see you do THAT with only one cannibal knowing how to row... you can't. the admin forgot to mention that.

the admin did not forget to mention anything ... in the spirit of other river crossing puzzles the wording of this puzzle is sufficient

btw, if you want to quote several posts, you can do that in one single reply and not increasing your post count by replying to more posts in several posts
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### #62 Charlie87

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Posted 09 November 2008 - 11:12 PM

ablissfulgal said:

Alternative Solution::

Cannibals are X's and Missionaries are O's

pick up two cannibals: in boat XX
leave one cannibal: left side of river X, right side of river X OOO
pick up one missionary: in boat XO
leave missionary: left side of river XO. right side X OO
pick up one missionary: in boat XO
leave missionary: left side of river XOO, right side XO
pick up one missionary: in boat XO
leave missionary: left side of river XOOO, right side of river X
pick up cannibal: in boat XX
leave both cannibals: left side of the river XXXOOO

The bold part is where you would have a missionary eaten. What you’ve got is a cannibal on the left side as well as a cannibal and missionary in the boat. Once the boat gets to the left side to drop the missionary off you’ve got 2 cannibals and 1 missionary on the left side. (When the boat is on the left, you count all in it towards the left sides totals. Same if it’s on the right.)

Graphically, missionary about to be dropped off:
(can)_[(can)(mis)]………….._(can)(mis)(mis)
^
Missionary is outnumbered in the dropoff. Gonna get eaten.

____.................................<-[(can)(mis)]_(can)(can)(mis)(mis)
(can)_.[(mis) ]->……….…...……..............……_ (can)(can)(mis)(mis)
(can)_................................<-[(can)(can)]_(mis)(mis)(mis)
(can)(can)_[(can)]->…….…………...............…_(mis)(mis)(mis)
(can)(can)_........................<-[(mis)(mis)]_(can)(mis)
(can)(mis)_[(can)(mis)]->…….…….........…..._(can)(mis)
(can)(mis)_........................<-[(mis)(mis)]_(can)(can)
(mis)(mis)(mis)_[(can)]->…….…….........…..._(can)(can)

Now all the missionaries are safe and across so the cannibal left with the boat can ferry the rest of the cannibals. At no point in time is a missionary with a greater number of cannibals (even including those sitting in the boat!)

artune, Thor7-10, stephcorbin, brownester, coolkid101, liz5000, seqee girl, theirish2121, and MangaMeggie have all made this mistake.

Nooooo, I can't believe even the ADMIN got it wrong!!!! thats not the answer. Only ONE cannibal knows how to row and again, he's on the wrong side!!! Thats gotta be embarrassing.
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### #63 Charlie87

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Posted 09 November 2008 - 11:16 PM

the admin did not forget to mention anything ... in the spirit of other river crossing puzzles the wording of this puzzle is sufficient

btw, if you want to quote several posts, you can do that in one single reply and not increasing your post count by replying to more posts in several posts

Oh ok, i didnt know that. I wasn't trying to make my post count higher though. But yo, only one cannibal knows how to row man, and I do have the correct solution for that.
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### #64 Maggi

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Posted 09 November 2008 - 11:56 PM

Oh ok, i didnt know that. I wasn't trying to make my post count higher though. But yo, only one cannibal knows how to row man, and I do have the correct solution for that.

I read your topic before it was deleted and I found the solution to the situation you mentioned (3 human - 3 cannibals - only 1 cannibal can row)

Spoiler for Here you go

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### #65 Charlie87

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Posted 10 November 2008 - 12:09 AM

I read your topic before it was deleted and I found the solution to the situation you mentioned (3 human - 3 cannibals - only 1 cannibal can row)

Spoiler for Here you go

Nope, sorry. Your second step leaves one human with 2 cannibals on the other side. All that would be too easy.
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### #66 Maggi

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Posted 10 November 2008 - 02:21 AM

Nope, sorry. Your second step leaves one human with 2 cannibals on the other side. All that would be too easy.

Oh yeah I see >.<
The fault was made due solving it too quickly and not paying enough attention.. Spent about 3 mins to solve it, explains a lot I guess..
Anyway, I can't seem to find the answer, I'd say it's impossible if only 1 cannibal knows how to row, unless you can give me the solution.
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### #67 Charlie87

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Posted 10 November 2008 - 03:22 AM

Oh yeah I see >.<
The fault was made due solving it too quickly and not paying enough attention.. Spent about 3 mins to solve it, explains a lot I guess..
Anyway, I can't seem to find the answer, I'd say it's impossible if only 1 cannibal knows how to row, unless you can give me the solution.

I could provide the solution, and i can assure there IS a solution, but if i tell you... what fun would that be? It took me for EVER to figure it out but i finally did. I knew of this a couple of years ago, i had given up on it quite a few times, but always took a stab at it every now and then.
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### #68 rookie1ja

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Posted 10 November 2008 - 10:53 AM

Nooooo, I can't believe even the ADMIN got it wrong!!!! thats not the answer. Only ONE cannibal knows how to row and again, he's on the wrong side!!! Thats gotta be embarrassing.

would you kindly show me in which step I made the fatal error?

Cannibals and Missionaries - Back to the River Crossing Puzzles
Three missionaries and three cannibals wanted to get on the other side of a river (Edited: all 6 of them have to get across alive). There was a little boat on which only two of them can fit. There can never be on one side more cannibals than missionaries because of a possible tragedy.

the implied information:
1. each cannibal and each missionary can row
2. whenever there are more cannibals than missionaries on one bank, the missionaries on that bank will be killed

Spoiler for Solution

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### #69 Maggi

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Posted 10 November 2008 - 02:48 PM

I could provide the solution, and i can assure there IS a solution, but if i tell you... what fun would that be? It took me for EVER to figure it out but i finally did. I knew of this a couple of years ago, i had given up on it quite a few times, but always took a stab at it every now and then.

Hmm yeah true that, I'll take another look at it today.. Actually this could be the same puzzle a friend of my moms gave me a few years ago, since it was also a river cross puzzle which at first sight seemed impossible, and after searching for a loooong time, I finally found it..

would you kindly show me in which step I made the fatal error?

There is no error in your solution, but I think what charlie was pointing out, is that ALL the cannibals can row in your situation, in charlies situation, only 1 cannibal can row, which makes it a lot harder to find the solution >.<
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### #70 Charlie87

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Posted 11 November 2008 - 12:31 PM

would you kindly show me in which step I made the fatal error?

Well, what maggi said is correct. There actually is no error in your solution given the fact that they don't state that only one cannibal knows how to row in the site where you got this puzzle from. Maybe there's different versions of it and i was aware of only the version i knew. I guess it just kinda made me mad that this one was simpler, and I was stuck on the idea that only one knows how to row, which does make the problem a lot harder.

I suppose I can apologize for saying that you were wrong for your particular version of this puzzle. But it would be nice if you solved the harder version . Also, if you try to do it with the only-one-rowing-cannibal version you would then see where the "fatal error" would be at that I was talking about. I'm sure it wont take you long to figure this one out since you already did the other one .
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