[Ammi]

....you find yourself in a situation where you are on a raft stranded at sea with raft-eating sharks chasing you.... on this raft are 10 other people...all 10 people and yourself are covering holes in the raft with their bodies to prevent water from entering the raft...you calculate that if you stay and help paddle on this raft with the others you will manage to travel fast enough to get away from the sharks for three times as long than if you were not there to paddle and help fill in the holes.....

...suddenly, you see your friend on a motor boat (that sharks cannot eat) who offers to you to get on and flee to safety....there is only enough fuel to carry two people...what do you do...?



Note that there is no way to adapt the raft to be powered by the lifeboat and save everyone, either you save yourself for sure or triple the likelihood of escaping the sharks for 10 people....assume that all of the people including yourself are naked with no items that are capable of filling in the holes even whilst you're away