Does any one know a help site for crossing the river with dogs for college student math book?

Try the 'related link' that I posted. A couple of tips. In most of these type problems, you usually end up bringing an item back before your final trip to get everything across. Also, usually there is at least one combination that is safe to leave together.

If you have a fox, a rabbit, and some cabbage. The fox won't eat the cabbage, but he'll eat the rabbit. The rabbit will eat the cabbage, so you take the rabbit first. Then come back empty, then take the fox over, then bring the rabbit back. Leave the rabbit and take the cabbage. Leave the cabbage and come back empty. Finally take the rabbit over.