1/n+2/n+...+(n-1)/n
=n(n-1)/2n
=(n-1)/2
1/2+1/3+2/3+1/4+2/4+3/4+1/5+2/5+3/5+4/5+.1/60+.59/60
=(1+2+3+...+59)/2
=59*60/(2*2)
=885
1/n+2/n+...+(n-1)/n
=n(n-1)/2n
=(n-1)/2
1/2+1/3+2/3+1/4+2/4+3/4+1/5+2/5+3/5+4/5+.1/60+.59/60
=(1+2+3+...+59)/2
=59*60/(2*2)
=885