Were you able to figure it out on your own or did you have to peek at the answer?
As Bumi once said you need to open your brains to the possibilities and the answer lies in two directions.
The farmer knows he cannot leave the fox with the chicken or the chicken with the corn unattended on either side of the river while transporting the third item. So here's how he does it.
The farmer takes the chicken over first, leaving the fox with the corn.
Then he goes back he takes the fox over next. But instead of leaving the fox and the chicken together while he goes back to get the corn, he takes the chicken back with him.
He leaves the chicken on the side he started on and then takes the corn over.
Leaving the corn and the fox, he goes back again to fetch the chicken. An now he got all three safely across!