There are 20 questions in one oral arithmetic competition, 5 points will be awarded for each correct answer, 5 points will be deducted for each wrong answer, and no points will be deducted if you do not answer the question. Dongdong did every question in the competition, and finally scored 60 points in the test. Do you know how many questions Dongdong got right?
一次口算比赛共20道题，做对一题得5分，做错一题倒扣5分，不做不得分也不扣分．东东在比赛中每道题都做了，最后考了60分，你知道东东做对了几道题吗？
<gadget id="calculator">20 * 5</gadget>
<output>100</output>

<gadget id="calculator">100 - 60</gadget>
<output>40</output>

<gadget id="calculator">5 + 5</gadget>
<output>10</output>

<gadget id="calculator">40 / 10</gadget>
<output>4</output>

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

<result>16</result>