Cars A, B, and C set off at the same time and at the same place to chase a cyclist in front along the same road. As a result, the three cars took 6 hours, 10 hours, and 12 hours to catch up with the cyclist. It is known that car A travels 24 kilometers per hour, and car C travels 19 kilometers per hour. Find the speed of car B?
甲、乙、丙三辆汽车同时同地出发，沿同一条公路去追赶前面一个骑车人，结果三辆车分别用了6小时、10小时、12小时追赶上骑车人．已知甲车每小时行24千米，丙车每小时行19千米，求乙车的速度？
<gadget id="calculator">24 * 6</gadget>
<output>144</output>

<gadget id="calculator">19 * 12</gadget>
<output>228</output>

<gadget id="calculator">228 - 144</gadget>
<output>84</output>

<gadget id="calculator">12 - 6</gadget>
<output>6</output>

<gadget id="calculator">84 / 6</gadget>
<output>14</output>

<gadget id="calculator">14 * 6</gadget>
<output>84</output>

<gadget id="calculator">144 - 84</gadget>
<output>60</output>

<gadget id="calculator">60 / 10</gadget>
<output>6</output>

<gadget id="calculator">6 + 14</gadget>
<output>20</output>

<result>20</result>