(1/2+1/3+1/4+…+1/60)+(2/3+2/4+2/5…+2/60)+(3/4+3/5+…+3/60)+…+(58/59+58/60)+59/60
问题描述:
(1/2+1/3+1/4+…+1/60)+(2/3+2/4+2/5…+2/60)+(3/4+3/5+…+3/60)+…+(58/59+58/60)+59/60
请尽快!
答
(1/2+1/3+1/4+…+1/60)+(2/3+2/4+2/5…+2/60)+(3/4+3/5+…+3/60)+…+(58/59+58/60)+59/60 =0.5+1+1.5+2+.+29.5 =(0.5+29.5)*59÷2 =885