There are 15 questions in a math contest. For each correct question, 8 points will be deducted, and for each wrong answer, 4 points will be deducted. Xiao Ming has done all the questions, but only scored 72 points. How many questions did he get right? (column calculation)
一次数学竞赛共15道题，每做对一道题得8分，做错一道倒扣4分，小明所有题都做了，可只得了72分，他做对了几道题？(列式计算)
<gadget id="calculator">15 * 8</gadget>
<output>120</output>

<gadget id="calculator">120 - 72</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">15 - 4</gadget>
<output>11</output>

<result>11</result>