There are 60 cars and two-wheeled motorcycles in the parking lot, and there are 168 wheels. How many cars are there?
停车场有小汽车和两轮摩托车共60辆，车轮共有168个，小汽车有多少辆．
<gadget id="calculator">60 * 4</gadget>
<output>240</output>

<gadget id="calculator">240 - 168</gadget>
<output>72</output>

<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">72 / 2</gadget>
<output>36</output>

<gadget id="calculator">60 - 36</gadget>
<output>24</output>

<result>24</result>