5 people receive 55 apples one by one, starting from the second person, each person has two more than the previous person. How much does the first person get?
5个人依次领取55个苹果，从第二人起，每人比前一人多两个．第一人得多少个．
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">8 * (5/2)</gadget>
<output>20</output>

<gadget id="calculator">55 - 20</gadget>
<output>35</output>

<gadget id="calculator">(5/2) + (5/2)</gadget>
<output>5</output>

<gadget id="calculator">35 / 5</gadget>
<output>7</output>

<result>7</result>