1×1/3+1/3×1/5+1/5×1/7+……+1/99×1/101

问题描述:

1×1/3+1/3×1/5+1/5×1/7+……+1/99×1/101

1×1/3+1/3×1/5+1/5×1/7+……+1/99×1/101
=(1/2)[1-(1/3)+(1/3)-(1/5)+(1/5)-(1/7)+……+(1/99)-(1/101)]
=(1/2)[1-(1/101)]
=50/101