My clever daughter(11) was the only kid in her class to get this right! Took me ages! I know you equally clever people will work it out!
A farmer must take a chicken, a fox and a bag of grain to market. He reaches a river which he has to cross by boat. He can only have one of the 3 things in the boat at any one time! However, he cannot leave the chicken with the grain or the fox with the chicken. He can make as many trips as is necessary to get himself and the 3 things to market! How does he do it?