In a scientific experiment, the students in the first group planted 180 soybeans, but 20 did not germinate; they replanted 20 more, and all germinated. What is the germination rate of the soybeans they planted?
在一次科学实验活动中，第一小组的同学种了180粒黄豆，结果有20粒没有发芽；他们又补种了20粒，全部发芽．他们种的黄豆的发芽率是多少．
<gadget id="calculator">20 - 20</gadget>
<output>0</output>

<gadget id="calculator">180 + 0</gadget>
<output>180</output>

<gadget id="calculator">180 + 20</gadget>
<output>200</output>

<gadget id="calculator">180 / 200</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(9/10) * 1</gadget>
<output>9/10 = around 0.9</output>

<result>9/10 = around 0.9</result>