river crossing - A Fox, a Chicken, a Pile of Seeds, and a Boat

There's 2 islands, 1 island has a pile of seeds, a chicken, and a fox. There's also a boat next to this island, you have to get it all across with minimum uses of the boat. You can only take one thing across at once. If you leave the fox and the chicken, the fox will eat the chicken, if you leave the chicken and the pile of seeds, the chicken will eat the seeds.

How can you do it, please provide an explanation, and total number of boat uses.

Answer

1. take the Chicken across - bring nothing back



2. take the Fox across - bring the Chicken back


3. take the Seeds across - bring nothing back


4. take the Chicken across

So, you will go there and back 3 times then go there with the Chicken at the end making 7 trips (3.5 round trips).