On Sunday, Xiaoqiang did interesting math problems. He has already done 12, and the rest is exactly three times as many as he has done. How many interesting math problems does Xiaoqiang have to do in total?
星期天，小强做趣味数学题，已经做了12道，剩下的正好是做完的3倍，小强一共要做多少趣味数学题．
<gadget id="calculator">12 * 3</gadget>
<output>36</output>

<gadget id="calculator">36 + 12</gadget>
<output>48</output>

<result>48</result>