题目
From an approved list of 25 funds, a portfolio manager wants to rank 4 mutual funds from most recommended to least recommended. Which formula is most appropriate to calculate the number of possible ways the funds could be ranked?
选项
A.Permutation formula
B.Multinomial formula
C.Combination formula
答案
A
解析
： A is correct. The permutation formula is used to choose r objects from a total of n objects when order matters. Because the portfolio manager is trying to rank the four funds from most recommended to least recommended, the order of the funds matters; therefore, the permutation formula is most appropriate. ： A正确。 当顺序重要时，用排列公式从n个对象中选择r个对象。由于投资组合经理试图将这四只基金从“推荐最多”排序为“推荐最少”，因此基金的顺序很重要;因此，排列公式是最合适的。