In detail

Missionaries and cannibals

Missionaries and cannibals

Three missionaries got lost exploring a jungle. Separated from their peers, without food and without radio, they only knew that to reach their destination they should always go forward. The three missionaries stopped in front of a river that blocked their passage, wondering what they could do. Suddenly, three cannibals appeared carrying a boat, because they also wanted to cross the river. Groups of missionaries and cannibals had been found before, and each respected the others, but without trusting them. The cannibals feast on missionaries when they outnumber them.

The three cannibals wanted to help missionaries cross the river, but their boat could not carry more than two people at a time and the missionaries did not want the cannibals to outnumber them.

How can the problem be solved, without at any time having more cannibals than missionaries on any bank of the river? Remember that a missionary and a cannibal on a riverbank plus one or two cannibals in the boat on the same side means that missionaries will have problems.

Solution


There is more than one solution to this problem. The one we show you is one of them, with eleven total movements, the minimum that can be achieved, but you can reach the same solution with small variations of them. Missionaries are represented with black dots and cannibals with white dots.