1×2分之1+2×3分1+...+2002×2003分之1
问题描述：
1×2分之1+2×3分1+...+2002×2003分之1
答
1×2分之1+2×3分1+...+2002×2003分之1
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+……(1/2002-1/2003)
=1-1/2+1/2-1/3+1/3-1/4+……+1/2002-1/2003
=1-1/2003
=2002/2003
答
=1-1/2+1/2-1/3+.+1/2002-1/2003
=1-1/2003
=2002/2003