1/24+1/120+1/360+1/840的解法,
问题描述:
1/24+1/120+1/360+1/840的解法,
请哪位哥哥,
答
1/24+1/120+1/360+1/840=(1/24)(1+1/5+1/15+1/35)=(1/24)*(105+21+7+3)/105=(1/24)*(136/105)=17/315