>I may have already given this one, but what the heck, I'll give it again.
>
>There are 3 missionaries and 3 natives. They need to cross a river in a boat that only holds 2. The restraints are that the cannibals can't outnumber the Missionaries on either side because the missionaries feared that the natives would over-power and eat them.

You always have a Cannibal [C] in the boat. Order of crossing:

1. Missionary.(left 2M and 2C, crossed 1M and 0C, 1C in the boat)
2. Cannibal...(left 2M and 1C, crossed 1M and 1C, 1C in the boat)
3. Missionary.(left 1M and 1C, crossed 2M and 1C, 1C in the boat)
4. Missionary.(left 0M and 1C, crossed 3M and 1C, 1C in the boat)
5. Cannibal...(left 0M and 0C, crossed 3M and 2C, 1C in the boat)

Now the Cannibal in the boat comes ashore.

Either that, or the missionaries all stay together until they convert one of the cannibals to christianity before crossing. :^)