The Frustrated Farmer: A Solution
In The Frustrated Farmer, a farmer needs to find a way to transport a fox, a chicken, and a bag of corn across a river in a boat. She could only take one thing at a time. If the fox was left alone with the chicken (on either side of the river), it would eat the chicken. Likewise, if the chicken was left alone with the bag of corn, it would eat the corn. To solve the puzzle, you were to find a way for the farmer to get the fox, the chicken, and the bag of corn safely across the river.
One possible solution to this puzzle follows. The farmer first takes the chicken across the river and leaves it on the other side. She then comes back and picks up the fox and takes it to the other side. When she gets there, she drops off the fox and brings the chicken back with her. She then drops the chicken off and picks up the bag of corn which she takes across the river. Finally, she goes back and picks up the chicken and takes it across the river one last time. When this is done, she has safely transported everything across the river and is able to go on her way.