在23579这5个数字中, 选出4个数字组成被3和5除都余2的四位数.这样的四位数有哪些
问题描述：
在23579这5个数字中, 选出4个数字组成被3和5除都余2的四位数.这样的四位数有哪些
答
2357,3257,5327,5237,3527,2537,
7352,3752,5372,5732,3572,7532,
2957,9257,5927,5297,9527,2597,
7952,9752,5972,5792,9572,7592.
就这些
答
2357,3257,5327,5237,3527,2537,
7352,3752,5372,5732,3572,7532,
2957,9257,5927,5297,9527,2597,
7952,9752,5972,5792,9572,7592.
答
由题意得,该数减2是15的倍数,所以减二后的数结尾一定是5或0.再选三个数与5相加得3的倍数,找出这样的四位数,再加2.所以是：
3797,3977,7397,7937,9737,9377,2372,2732,3722,3272,7232,7322,2792,2972,7292,7922,9722,9272
共18个