Question

用8张卡片组成两个三位数，使它们的和是1000。你能写出几组？数字有1、2、3、4、5、6、7、8、

Answer 1

24道，加法交换律两个加数交换的略。

124 + 876 = 1000
126 + 874 = 1000
143 + 857 = 1000
147 + 853 = 1000
153 + 847 = 1000
157 + 843 = 1000
174 + 826 = 1000
176 + 824 = 1000
214 + 786 = 1000
216 + 784 = 1000
284 + 716 = 1000
286 + 714 = 1000
342 + 658 = 1000
348 + 652 = 1000
352 + 648 = 1000
358 + 642 = 1000
413 + 587 = 1000
417 + 583 = 1000
432 + 568 = 1000
438 + 562 = 1000
462 + 538 = 1000
468 + 532 = 1000
483 + 517 = 1000
487 + 513 = 1000

http://zhidao.baidu.com/link?url=x1HCCunpY_oCjbO7WJFrqh3To8eRz6sJMfhfAW1kWjQs4sc9rpLLfoXOch0nzFObqTLKP5xgQjpAFEwSuThqCq