SAT 数学题 谁给解释一下?Of 5 employees, 3 are to be assigned an offic

SAT 数学题 谁给解释一下?
Of 5 employees, 3 are to be assigned an office and 2 are to be assigned a cubicle. If 3 of the employees are men and 2 are women, and if those assigned an office are to be chosen at random, what is the probability that the offices will be assigned to 2 of the men and 1 of the women?
5名员工,3个人可以分到办公室,2个分到隔间,3男2女 随机安排,有多少种可能性,分到办公室的人为2男1女?
答案是 3/5 可是为什么啊?这种题应该怎么做?
谢谢 各位,列举我是明白了,可是这从5中选3个有什么公式什么之类的吗,阶乘如何乘?