After a storm, the ship you were traveling on is shipwrecked. Before leaving you have the opportunity to take something that is useful; you have to choose between a box of nails or a hammer. You can't take everything, you must quickly decide on one thing or the other,
What would you choose
But the misfortunes are not over here. On the island where you have gone, covered with vegetation, there is a fire on the opposite side to where you are and, for greater misfortune, the wind blows towards you. What will you do to save life? Throw yourself into the sea or wait until everything has burned? Can not be! Look how unhappy you are, sharks attracted to the wreck around the coast.
What to do? Know that the fire is coming.
An intelligent person will choose the nails, because a hammer can be improvised with any stone, but replacing some nails is almost impossible and can be very useful.
For the other problem, the best solution would be for you to go to the center of the island and cause a new fire, meanwhile you could stay between the two fires. When the first fire arrived, you could save yourself by placing yourself in the area already burned by the second fire, since the first one would be extinguished by not finding anything to burn.