## Friday, June 17, 2005

### Raft Puzzle

Here's a puzzle I just heard about today. I found it enjoyable.

We have the following people on one side of a river: Policeman, Criminal, Parent A, Parent A's two children, Parent B, and Parent B's two children. There is a 2-person raft available for use. Only the Policeman and the two Parents know how to control the raft. The goal is to move all the people to the other side of the river.

Criminal cannot be with anyone without the presence of the Policeman.
Parent A cannot be with any of Parent B's children without the presence of Parent B.
Parent B cannot be with any of Parent A's children without the presence of Parent A.

Have fun.

Spud said...

1) Policeman and Criminal cross first.
2) Policeman comes back alone.
3) Policeman and Child A1 cross over together.
4) Policeman and Criminal come back together.
5) Parent A and Child A2 cross over to join Child A1.
6) Parent A comes back alone.
7) Parent A and Parent B cross over together to join Child A1 and A2.
8) Parent B comes back alone.
9) Policeman and Criminal cross over together.
10) Parent A comes back alone.
11) Parent A and Parent B cross over together.
12) Parent B comes back alone.
13) Parent B and Child B1 cross over.
14) Policeman and Criminal come back together.
15) Policeman and Child B2 cross over together.
16) Policeman comes back alone.
17) Policeman and Criminal cross over together.

Tim said...

I've heard this one before but it was with a guy with a chicken, a fox and some corn. He had to cross the river but the could only take one item across at a time. Since the fox would eat the chicken and the chicken would eat the corn, there was a dilemma. The solution is the same as spud's.