There are 20 questions in a certain quiz, 5 points are awarded for 1 correct answer, 1 point is deducted for wrong or non-answered 1 question, Serena gets 76 points, how many questions does he answer correctly.
某次智力竞赛有20道题，答对1道题得5分，答错或不答1道题倒扣l分，小威得76分，他答对多少道题．
<gadget id="calculator">20 * 5</gadget>
<output>100</output>

<gadget id="calculator">100 - 76</gadget>
<output>24</output>

<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<gadget id="calculator">24 / 6</gadget>
<output>4</output>

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

<result>16</result>