First he brings the chicken to the far side, leaving fox and seed.
He returns, then brings the seed to the far side, but returns with the chicken, leaving seed alone on the far side.
He brings the fox to far side and leaves it with the seed, returns empty.
He brings the chicken to far side and is finished.
Alimentary, dear non-Watson.
And, he is correct!
Maggie O. from my 4th grade class was the one who solved the puzzle then and the visitor who posed the puzzle said to her, "I like the way you think."
So, dad, I like the way you think. You were always good at puzzles and analysis.
It helps to have a problem to solve regularly to keep our brains healthy.
I will try to find more to post.