问题标题:
很难的简算题1/6+1/24+1/60+1/120+1/210+1/336+1/112=?
问题描述:
很难的简算题
1/6+1/24+1/60+1/120+1/210+1/336+1/112=?
孙振书回答:
1/6+1/24+1/60+1/120+1/210+1/336+1/112
=(1/6+1/24)+(1/60+1/120)+1/210+(1/336+1/112)
=5/24+1/40+1/210+1/77
=7/30+1/210+1/77
=5/21+1/77
=38/147