There are 12 trucks in the parking lot, the number of buses is three times that of trucks, and 7 cars are as many as buses. How many cars are there?
停车场有12辆卡车，大客车的辆数是卡车的3倍，小汽车开走7辆就与大客车同样多，小汽车有多少辆？
<gadget id="calculator">12 * 3</gadget>
<output>36</output>

<gadget id="calculator">36 + 7</gadget>
<output>43</output>

<result>43</result>