巧填数字——质数幻五环

来源:百度知道 编辑:UC知道 时间:2024/06/25 23:14:32
请把15个质数:11,29,59,89,139,211,229,311,439,479,499,599,619,839,859填入图中空白处,使五个圈内各数之和都等于2008,正好是第29届北京奥运会召开的年份,你能完成吗?

PS:图我不会弄,就是像奥运五环那样。各位高手帮帮忙,这是《时刻准备着》数学六年级寒假作业里的

主圆中间:229,其余:499,211,59,11,89,311,599
子圆: 439,859;
859,29,839;
839,139,619;
619,479.

229+499+211+59+11+89+311+599=2008
499+211+439+859=2008
211+59+11+859+29+839=2008
11+89+311+619+839+139=2008
311+599+619+479=2008

很简单,这里最多的是个位为9的数,只要排除。
若有5个9,9*5=45,五数和个位为5,排除。
若有4个9,9*4=36,剩下的数个位必为2,无,排除。
若有3个9,9*3=27,剩下的两数个位和必为1,无,排除。
若有2个9,9*2=18,剩下的三数个位和必为0,无,排除
只有剩下三个个位不是9的数,题目有问题

我不知道!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

真难