1乘3/1+3乘5/1+······99乘101/1等于（ ）
问题描述：
1乘3/1+3乘5/1+······99乘101/1等于（ ）
答
1乘3/1+3乘5/1+······99乘101/1
=1/2(1-1/3+1/3-1/5+1/5-1/7+.1/99-1/101)
=1/2(1-1/101)
=1/2×100/101
=50/101
101分之50