Xiao Ming has done 20 questions. If he gets 5 points for a correct question, 2 points will be deducted for a wrong question. Xiao Ming gets 72 points. How many questions did he get right?
小明做了20个题目，做对一题得5分，做错一题倒扣2分，小明得了72分，他做对了几道？
<gadget id="calculator">40 + 72</gadget>
<output>112</output>

<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">112 / 7</gadget>
<output>16</output>

<result>16</result>