1+1/2+1/3+2/3+1/4+2/4+3/4+...59/60

问题描述:

1+1/2+1/3+2/3+1/4+2/4+3/4+...59/60

1/n+2/n+……+(n-1)/n
=([1+2+……+(n-1)]/n
=[n(n-1)/2]/n
=(n-1)/2
所以原式=1+1/2+2/2+3/2+……+59/2
=1+(1+2+……+59)/2
=1771