The length of the railway between A and B is 780 kilometers. A train travels from A to B and travels 25% of the whole journey in 3 hours. According to this calculation, how many hours will it take to complete the journey?
甲乙两地铁路长780千米，一列火车从甲地开往乙地，3小时行了全程的25%，照这样计算，行完全程共需多少小时？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) / 3</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">780 * (1/12)</gadget>
<output>65</output>

<gadget id="calculator">780 / 65</gadget>
<output>12</output>

<result>12</result>