Required Mathematical Intelligence

Chapter 68 Missionaries and Barbarians

The three missionaries and the three savages were at the crossing of a small river, where there was only one small boat that could accommodate two people.The object of the problem is to use this small boat to ferry all these six people to the opposite bank. The condition is that during the process of crossing the river, the number of missionaries on both sides of the river is kept at any time by no less than the number of savages, otherwise the savages will make the minority missionaries eat.How can these six people get across safely?
[Answer: You can cross the river like this

1. A priest crosses a river with a barbarian;

2. Leave the barbarians behind, and the priest returns;

3. Two savages cross the river;
4. A barbarian returns;

5. Two priests cross the river;

6. A priest and a barbarian return;

7. Two priests cross the river;

8. A barbarian returns;

9. Two savages cross the river;
10. A barbarian returns;

11. Two savages cross the river.

The key step here is step 6. Many people can't solve this problem because they didn't think of this step. ]
(End of this chapter)