>>The boat always has to be piloted by a missionary or a cannibal.
>
>Then if a cannibal in the boat counts toward the total on whichever side he is on, I can't see any scenario of crossing order that meets the requirement of cannibals never outnumbering the missionaries on either side. Unless there is a trick answer.

The trick is in realising that you are not restricted to 1 person on the return journey, 2 people can return in the boat.