用2,5,4,0,1这五个数字按要求组数.（2）组成含有因数2的四位数（有多少写多少!）
问题描述：
用2,5,4,0,1这五个数字按要求组数.（2）组成含有因数2的四位数（有多少写多少!）
答
含因数2就是双数,以2,4,0结尾的组合都可以
以0结尾
1240,1250,1420,1450,1520,1540,2140,2150,2410,2450,2510,2540
4120,4150,4210,4250,4510,4520,5120,5140,5210,5240,5410,5420
以2结尾
1042,1052,1402,1452,1502,1542,4012,4052,4102,4152,4502,4512
5012,5042,5102,5142,5402,5412
以4结尾
1024,1054,1204,1254,1504,1524,2014,2054,2104,2154,2504,2514
5014,5024,5104,5124,5204,5214