A certain school held a scientific knowledge contest, with a total of 10 questions, 20 points for each correct answer, and 10 points deducted for wrong answers or no answers. Wang Li scored 110 points in this competition. How many questions did he answer correctly?
某校举行科学知识竞赛，共10题，答对一题加20分，答错或不答扣10分，王力在本次竞赛中得分是110分，他答对了几道题？
<gadget id="calculator">10 * 20</gadget>
<output>200</output>

<gadget id="calculator">200 - 110</gadget>
<output>90</output>

<gadget id="calculator">20 + 10</gadget>
<output>30</output>

<gadget id="calculator">90 / 30</gadget>
<output>3</output>

<gadget id="calculator">10 - 3</gadget>
<output>7</output>

<result>7</result>