1到100含5的数有多少?答:1到100含5的数有5,15,25,35,45,50,51,52,53.54,55,56,57,58,59,65,75,85,95,共计19个。
1到900的连续自然数中,各位上数字有5的共有多少个?答:有90个,因为1~100各位上是5的有5,15,25,35,45,55,65,75,85,95.共有十个。10*9=90
输出1到9999中能被7整除,而且至少有一位数字是5的所有数字答:35,56,105,154,175,245,252,259,315,350,357,385,455,504,511,518,525,532,539,546,553,560,567,574,581,588,595,651,658,665,735,756,805,854,875,945,952,959,1015,1050,1057,1085,1155,1225,1253,1295,1351,1358,1365,1435,1456,1505,1512,1519,1526,1533,1540,1547,1554,1561,...