A train travels from Beijing to Guangzhou and travels the entire distance (2/15) in 4 hours. According to this calculation, how many hours will it take to complete the journey?
一列火车从北京开往广州，4小时行驶了全程的(2/15)，照这样计算，行驶完全程共需多少小时．
<gadget id="calculator">2 / 15</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">(2/15) / 4</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">1 / (1/30)</gadget>
<output>30</output>

<result>30</result>