题目；1-1/10-1/100-1/1000-……-1/10000000000
问题描述：
题目；1-1/10-1/100-1/1000-……-1/10000000000
答
=1-（0.1+0.01+...+0.0000000001）
=1-0.1111111111
=0.8888888889