六年级数学奥数题1+1/3+1/6+1/10+1/ - 知识问答

六年级数学奥数题1+1/3+1/6+1/10+1/15+...+1/5050=?

7个回答

1+1/3+1/6+1/10+1/15
=2(1/1-1/2)+2(1/2-1/3)+2(1/3-1/4)+2(1/5-1/6)+...+2(1/100-1/101)
=2(1/1-1/2+1/2-1/3+1/3-1/4+1/5-1/6+...+1/100-1/101)
=2(1/1-1/101)
=2*100/101
=200/101

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