There are 20 questions in a mathematics competition. 8 points are awarded for a correct answer, and 4 points are deducted for an incorrect answer or no answer. Liu Dong scored 112 points, how many questions did he get right.
一次数学竞赛共有20道题．做对一题得8分，做错一题或不答均倒扣4分．刘冬得了112分，他做对了多少题．
<gadget id="calculator">20 * 8</gadget>
<output>160</output>

<gadget id="calculator">160 - 112</gadget>
<output>48</output>

<gadget id="calculator">8 + 4</gadget>
<output>12</output>

<gadget id="calculator">48 / 12</gadget>
<output>4</output>

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

<result>16</result>