1/2+6/5+11/12+...+/109/110
=(1-1/2)+(1-1/6)+(1-1/12)+…+(1-1/110)
=10-(1/2+1/6+1/12+…+1/110)
=10-[(1-1/2)+(1/2-1/3)+(1/3-1/4)+…+(1/10-1/11)】
=10-[1-1/2+(1/2-1/3+1/3-1/4+…+1/10-1/11】
=10-(1-1/11)
=10-10/11
=100/11
1/2+6/5+11/12+...+/109/110
=(1-1/2)+(1-1/6)+(1-1/12)+…+(1-1/110)
=10-(1/2+1/6+1/12+…+1/110)
=10-[(1-1/2)+(1/2-1/3)+(1/3-1/4)+…+(1/10-1/11)】
=10-[1-1/2+(1/2-1/3+1/3-1/4+…+1/10-1/11】
=10-(1-1/11)
=10-10/11
=100/11