首先题目应该写成1/8+1/15+1/24+……+1/143
1/8+1/15+1/24+……+1/143
=1/(2*4)+1/(3*5)+(4*6)+……+1/(11*13)
=1/2*[1/2-1/4+1/3-1/5+1/4-1/6+……+1/11-1/13]
=1/2*(1/2+1/3-1/12-1/13)
=105/256
首先题目应该写成1/8+1/15+1/24+……+1/143
1/8+1/15+1/24+……+1/143
=1/(2*4)+1/(3*5)+(4*6)+……+1/(11*13)
=1/2*[1/2-1/4+1/3-1/5+1/4-1/6+……+1/11-1/13]
=1/2*(1/2+1/3-1/12-1/13)
=105/256