Question

题目是若1△=1 2△=1+1/2 3△=1+1/2+1/3 4△=1+1/2+1/3+1/4 5△=1+1/2+1/3

Answer 1

6△-5△=(1+1/2+1/3+1/4+1/5+1/6)-(1+1/2+1/3+1/4+1/5)=1/6