(1/3+1/6+1/9+1/15+1/60)/(1/2+1/4+1/6+1/10+1/40)
问题描述:
(1/3+1/6+1/9+1/15+1/60)/(1/2+1/4+1/6+1/10+1/40)
要简便算法
答
(1/3+1/6+1/9+1/15+1/60)/(1/2+1/4+1/6+1/10+1/40)
=(1/3)(1+1/2+1/3+1/5+1/20)/[(1/2)(1+1/2+1/3+1/5+1/20)]
=(1/3)/(1/2)
=2/3