1/3 × 2/5+1/5 2/7+1/7 2/9+……1/99 × 2/101

问题描述:

1/3 × 2/5+1/5 2/7+1/7 2/9+……1/99 × 2/101

1/3 × 2/5+1/5 ×2/7+1/7 ×2/9+……1/99 × 2/101
=1/3-1/5+1/5-1/7+1/7-1/9+.+1/99-1/101
=1-1/101
=100/101