After testing, the survival rate of a sapling is in the range of 80%-90%, if it is necessary to ensure that 360 saplings are planted alive. So at least how many saplings should be planted.
经试验，一种树苗的成活率在80%-90%范围内，如果要保证栽活360棵树苗．那么至少要栽多少棵树苗．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">360 / (4/5)</gadget>
<output>450</output>

<result>450</result>