The duckweed in a pond doubles every day, and the duckweed will cover the whole pond in 24 days. Calculate how many days the duckweed can cover the whole pond (1/4).
一个池塘浮萍每天增长一倍，24天浮萍会长满整个池塘，算算看第多少天浮萍能长满整个池塘的(1/4)．
<result>22</result>