A bacterium divides once every minute, one divides into two, and two divides into four... If a bacterium is put into a bottle and the whole bottle is filled after 10 minutes, how many minutes will it take to fill the empty bottle (1/4 ).
一种细菌每分钟分裂一次，由一个分为两个，两个分为四个…如果将一个细菌放入瓶中，10分钟后充满整瓶，那么多少分钟后充满空瓶的(1/4)．
<result>8</result>