Lahm got 72 points for participating in the math competition. There are 20 questions in this competition. If you get a question right, you get 5 points. If you do something wrong or don’t do it, you will not only get no points, but you will also be deducted 2 points. How many questions did Lahm get right? question?
拉姆同学参加数学竞赛得了72分，此次竞赛共有20道题，做对一题得5分，做错或不做不但不得分还要倒扣2分，拉姆同学一共做对了多少道题？
<gadget id="calculator">5 * 20</gadget>
<output>100</output>

<gadget id="calculator">100 - 72</gadget>
<output>28</output>

<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">28 / 7</gadget>
<output>4</output>

<gadget id="calculator">20 - 4</gadget>
<output>16</output>

<result>16</result>