Question

Help! word problem!
There are three cannibals and three missionaries at the edge of a river. There is a small raft which can carry only two people. If, at any time, there are more cannibals than missionaries on either side of the river, the cannibals will gang up and eat the missionaries. (Staying in the boat is not an option; if the boat is on one side of the river, so is anyone in the boat.) How do they cross the river without anyone being eaten?

Answer 1

I really like this question.

Answer 2

You might have to draw a diagram and work it out.

Answer 3

@TheSmartOne @nightwielder

Answer 4

ok ill try to draw a diagram and see if i can get it. thanks!

Answer 5

You're welcome.

Answer 6

Let M1, M2, M3 be the three missionaries.
Let C1, C2, C3 be the three cannibals

1. M1 + C1 go to the other side. C1 is dropped off. M1 returns:
Side 1: {M2, M3, C2, C3}; Side 2: {C1}
2. M1 picks up C2. They travel to side 2. M1 drops off. C2 returns:
Side 1: {M2, M3, C3}; Side 2: {C1, M1}
3. C2 picks up M2. They travel to side 2. M2 drops off. C2 returns:
Side 1: {M3, C3}; Side 2: {C1, M1, M2}
4. C2 picks up C3. They travel to side 2. C2 drops off. C3 returns:
Side 1: {M3}; Side 2: {C1, M1, M2, C2}
5. C3 picks up M3. They travel to side 2. Both drop off:
Side 1: {}; Side 2: {C1, M1, M2, C2, M3, C3}

Answer 7

setting it up this way makes more sense. Thanks!

Answer 8

You are welcome.