Put eggs in a basket, assuming that the number of eggs in the basket doubles every minute, if you put it down like this, the basket will be full in 10 minutes. So, how many minutes exactly put half a basket of eggs.
往一个篮子里放鸡蛋，假定篮子里的鸡蛋数目每分钟增加1倍，这样放下去，10分钟时，篮子放满了．那么，多少分钟时恰好放入半篮子鸡蛋．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<result>9</result>