Using all of the digits 1,2,3,4,and 5 only once for each number,you can make 120 different numbers.If you put these numb
问题描述：
Using all of the digits 1,2,3,4,and 5 only once for each number,you can make 120 different numbers.If you put these numbers in an increasing order,what number is the 75th?
需要算式,没算式要原因.
答
第75个数是：41325
一共有120个数,万位是1的有120/5=24个.万位是2的也有24个；万位是3的也有24个,这样有共有72个,那么第73个数为41235,第74个数是41253,第75个数是41325.
这样解释可以了吗?