The fast, medium and slow cars set off from point A at the same time to catch up with a moving bicycle. The speeds of the three cars are 24 kilometers per hour, 20 kilometers per hour, and 19 kilometers per hour respectively. It took 6 hours for the fast train to catch up with the bicycle, 10 hours for the medium car to catch up with the bicycle, how many hours did it take for the slow train to catch up with the bicycle?
快、中、慢三车同时从A地出发，追赶一辆正在行驶的自行车，三车速度分别是每小时24千米、20千米、19千米．快车追上自行车用了6小时，中车追上自行车用了10小时，慢车追上自行车用多少小时？
<gadget id="calculator">20 * 10</gadget>
<output>200</output>

<gadget id="calculator">24 * 6</gadget>
<output>144</output>

<gadget id="calculator">200 - 144</gadget>
<output>56</output>

<gadget id="calculator">10 - 6</gadget>
<output>4</output>

<gadget id="calculator">56 / 4</gadget>
<output>14</output>

<gadget id="calculator">24 - 14</gadget>
<output>10</output>

<gadget id="calculator">19 - 14</gadget>
<output>5</output>

<gadget id="calculator">6 / 5</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">10 * (6/5)</gadget>
<output>12</output>

<result>12</result>