数学1.2.3……20这20个自然数中,每次取出3个不同的数,使这3个数的和是3的倍

2025-03-21 22:31:38
推荐回答(2个)
回答(1):

1,2......3/6/9/12/15/18
1,3......5/8/11/14/17/20
1,4......7/10/13/16/19
1,5......6/9/12/15/18
1,6......8/11/14/17/20
1,7......10/13/16/19
1,8......9/12/15/18
1,9......11/14/17/20
1,10......13/16/19
1,11......12/15/18
1,12......11/14/17/20
1,13......13/16/19
1,14......15/18
1,15......17/20
1,16......19
1,17......18
1,18......20
59种

回答(2):

13