Missionaries Games Missionaries And Cannibals Answer

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Answer: The missionaries and cannibals problem, and the closely related jealous husbands problem, are classic river-crossing logic puzzles.1 The missionaries and cannibals problem is a well-known toy problem in artificial intelligence, where it was used by Saul Amarel as an example of problem representation.

This riddle is slightly different from the puzzle with wolf goat and cabbage. It is a bit more complicated.

  1. There are four missionaries and four cannibals. The problem is now unsolvable. There is an oar on each bank. One person can cross in the boat with just one oar, but two oars are needed if the boat is to carry two people. One of the missionaries is Jesus Christ. Here we are using cultural literacy.
  2. For the Missionaries and Cannibals problem, this is simply having all three missionaries and all three cannibals on the opposite side of the river. The demo project attached actually contains a Visual Studio 2005 solution, with the following three classes: Program. Is the main entry point into the CannMissApp application.
  3. 6 Questions Sons Of The Forest Should Answer. While The Forest was a fantastic horror game, it left several questions without answers that the sequel needs to cover.
  4. Answer from: Dazzling Queen Take 1 cannibal and 1 missionary first and missionary return 2 cannibals go 1will return 2 missionaries go 1 cannibal go pick the 2nd and 3rd and go.

A river. Three cannibals and three missionaries are standing on one bank. There is a boat with maximum capacity of two people. How do they get to the other side so that missionaries are never outnumbered by cannibals on any bank?

Missionaries Games Missionaries And Cannibals Answer Key

Hint

There can be two people on the boat even on the way back or someone who has already been on the other side can go back. Try to draw the situation.

Answer

Cannibal and missionary there (or two cannibals). Missionary back (cannibal).

Two cannibals there one back.

Two missionaries there. Missionary and cannibal back.

Two missionaries there.

Now three missionaries and a cannibal moved to the other bank. The cannibal can now travel his friends one by one.

Too easy?

Go to very hard riddles and difficult brain teasers.

Too difficult?

Try easy puzzles for kids and funny riddles.

Rivercrossing and Runaway Math Puzzles

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Next:Nonmonotonic reasoningMissionaries games missionaries and cannibals answer sheetUp:ELABORATION TOLERANCE Previous:Introduction

The missionaries and cannibals problem (abbreviated MCP):

Three missionaries and three cannibals come to a river and find a boat that holds two. If the cannibals ever outnumber the missionaries on either bank, the missionaries will be eaten.
How shall they cross?

We call this original version of the problem MCP0.

Saul Amarel proposed [Ama71]: Let a state be given bythe numbers of missionaries, cannibals and boats on the initial bankof the river. The initial situation is represented by and thegoal situation by .

Most AI texts that mention the problem accept this formulation andgive us the solution:


The state space of the Amarel repreentation has 32 elements some ofwhich are forbidden and two of which are unreachable. It is anelementary student exercise to write a program to search the space andget the above sequence of states, and people are always solving itwithout a computer or without even a pencil. Saul Amarel[Ama71] points out that this representation has fewer statesthan a representation with named missionaries and cannibals.

What more does this problem offer AI?

If one indeed begins with the Amarel representation, the problem isindeed trivial. However, suppose we want a program that begins, aspeople do, with a natural language presentation of the problem.It is still trivial if the program need only solve the missionariesand cannibals problem. The programmer can then cheat as much as helikes by making his program exactly suited to the MCP. The extreme ofcheating is to make a program that merely prints



Readers will rightly complain that this cheats, but it isn't clearwhat does and doesn't count as cheating when a method for solvinga single problem is asked for.

The way to disallow cheating is to demand a program that can solve anyproblem in a suitable set of problems. To illustrate this we considera large set of elaborations of MCP. It won't be trivial to make aprogram that can solve all of them unless the human sets up each ofthem as a state space search analogous to the original MCP. We demandthat the program use background common sense knowledge like that aboutrivers and boats that is used by a human solver.

We skip the part about going from an English statement of the problemto a logical statement for two reasons. First, we don't have anythingnew to say about parsing English or about the semantics of English.Second, we don't yet have the logical target language that the parsingprogram should aim at. Progress toward establishing this language isthe goal of the paper.

The problem is then to make a program that will solve any of theproblems using logically expressed background knowledge. Thebackground knowledge should be described in a general way, notspecifically oriented to MCP and related problems.

This much was already proposed in [McC59]. What is new in thepresent paper is spelling out the idea of elaboration tolerancethat was distantly implicit in the 1959 paper. We require aformulation of MCP that readily tolerates elaborations of the problemand allows them to be described by sentences added to the statement ofthe problem rather than by surgery on the problem. We can call theseadditive elaborations. English languageformulations allow this, but the Amarel-type formulations do not. AIrequires a logical language that allows elaboration tolerantformulations.

We begin a few examples of English language elaboration tolerance.After discussing situation calculus formalisms, there will be a lotmore.

Missionaries
  • The boat is a rowboat. (Or the boat is a motorboat). This elaboration by itself should not affect the reasoning. By default, a tool is usable. Later elaborations make use of specific properties of rowboats.
  • There are four missionaries and four cannibals. The problem is now unsolvable.
  • There is an oar on each bank. One person can cross in the boat with just one oar, but two oars are needed if the boat is to carry two people.
  • One of the missionaries is Jesus Christ. Four can cross. Here we are using cultural literacy. However, a human will not have had to have read Mark 6:48-49 to have heard of Jesus walking on water.
  • Three missionaries with a lone cannibal can convert him into a missionary.

A later section discusses the formal problems of these and other elaborations.


Missionaries Games Missionaries And Cannibals Answers

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Missionaries And Cannibals Games

Introduction

Missionaries And Cannibals Play

John McCarthy
2003-09-29