包工程都要有资质:一题奥数!小学的

来源:百度文库 编辑:查人人中国名人网 时间:2024/05/14 04:27:32
1-(1010101/2020202)*(1010101/2020202)*(202020/303030)*(202020/303030)*(330333/550555)*(330333/550555)*(555500/777700)*(555500/777700)

原题=1-101/202*101/202*20/30*20/30*3/5*3/5*5/7*5/7
=1-1/2*1/2*2/3*2/3*3/5*3/5*5/7*5/7
=1-1/2*2*1/7*1/7
=1-1/49
=48/49

其中的202020和303030,都可以约掉的,你最后的算式是不是错了啊?

答案为49分之48
题目简化为1-(1/2)*(1/2)*(2/3)*(2/3)*(3/5)*(3/5)*(5/7)*(5/7)

=1-(1/7)*(1/7)=48/49

1-(1/2)*(1/2)*(2/3)*(2/3)*(3/5)*(3/5)*(5/7)*(5/7)
=1-(1/49)=48/49

=1-(1/2)*(1/2)*(2/3)*(2/3)*(3/5)*(3/5)*(5/7)*(5/7)
=1-1/49(约去2,3,5之后)
=48/49