In order to welcome the World Expo, the school organizes students from Class 5 (1) to make lanterns. If 8 people can be added, it can be completed in 10 days; if 3 people can be added, it will take 20 days to complete. Since other classes in the school have to practice other items, the school can only add 2 people to Class 5 (1), then How many days will it take for five (one) classes to finish these lanterns?
为了迎接世博会，学校组织五(一)班学生做灯笼．如果能增加8个人，10天就能做成；如果能增加3个人，就要20天才能完成，由于学校其他班级要练习其他项目，现在学校只能给五(一)班增加2个人，那么做完这些灯笼五(一)班需要多少天？
<gadget id="calculator">8 * 10</gadget>
<output>80</output>

<gadget id="calculator">3 * 20</gadget>
<output>60</output>

<gadget id="calculator">80 - 60</gadget>
<output>20</output>

<gadget id="calculator">20 + 80</gadget>
<output>100</output>

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

<gadget id="calculator">2 + 2</gadget>
<output>4</output>

<gadget id="calculator">100 / 4</gadget>
<output>25</output>

<result>25</result>