Question 121
Nine skiers participated in a race. They started one by one, and each skier passed the distance Determine if it could happen this each skier participated in an overtake (In each overtaking, exactly two skiers participated: the one who overtakes and the one who is overtaken.) Nine skiers left the start in turn and covered the distance - each with with its constant speed. Could it be that each skier participated exactly in four overtaking? (Every overtaking involves exactly two skiers - the one who overtakes, and the one who is overtaken.)