A farmer has a wolf, a chicken, and a bag of grain he needs to get accross a river. He has one boat to take them all across. He can only take one at a time. He cant leave the wolf alone with chicken or the chicken alone with grain. How does he do it?
He takes chicken first. He takes the wolf over second and comes back with the chicken. He drops of the chicken and takes the grain to the other side with the wolf. Last he goes back to get the chicken and brings him across.