The school held a math competition with 25 questions. Each correct answer was awarded 6 points, and 3 points were deducted for wrong answers or no answers. Xiaolei finally scored 114 points. How many questions did he answer correctly?
学校举行数学竞赛共25道题，每答对一道题得6分，答错或没有答都扣3分，小雷最后得了114分，他答对了多少道题．
<gadget id="calculator">25 * 6</gadget>
<output>150</output>

<gadget id="calculator">150 - 114</gadget>
<output>36</output>

<gadget id="calculator">6 + 3</gadget>
<output>9</output>

<gadget id="calculator">36 / 9</gadget>
<output>4</output>

<gadget id="calculator">25 - 4</gadget>
<output>21</output>

<result>21</result>