In order to green the city, a community needs to plant a batch of saplings, and the survival rate of these saplings is 80% to 90%. If you want to ensure that 720 trees are planted alive, at least how many saplings must be planted.
为了绿化城市，某小区要栽种一批树苗，这批树苗的成活率是80%～90%．如果要确保栽活720棵，至少要栽种多少棵树苗．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">720 / (4/5)</gadget>
<output>900</output>

<result>900</result>