Two of the five three-good students will participate in the city's three-good student congress. Among them, what is the possibility that Dongdong and Fangfang will be sent to attend the conference together?
5名三好学生中有两人要参加市三好学生代表大会．其中冬冬和芳芳一同派去参加大会的可能性是多少．
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">2 * 1</gadget>
<output>2</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>