题目甲、乙、丙、丁四人做相互传球练习,第一次由甲任意传给除甲外其他三人中的一人,第二次由接球者再将球任意传给其他三人中的一人,这样共传了4次球仍回到甲手中,则不同的传球方式有多少种?这是近几年比较流行的一道“传球”组合问题,对该题的理解及处理方式不同,得到的解法也不同,以下给出该问题的三种解法供读 Title A, B, C, D four people to do the practice of passing each other, for the first time from A to pass any of the other three in addition to a person, the second by the receiver then the ball to pass the other three In which a total of 4 times the ball is still back to the hands of A, how many different ways of passing? This is more popular in recent years a “pass” combination of questions, the understanding of the problem And the way of treatment is different, the solution is different, the following three solutions to the problem for reading