The fox will eat the chicken and the chicken will eat the corn. The farmer can only take one of the objects in the boat with him. First move - take the chicken over and leave it on the far bank. Come back and collect the fox. Take him over, drop him off, pick up the chicken and take it back to the first side. Drop chicken, pick up the corn and ferry it across. return empty, pick up the chicken and go back across again. Job done!