A pile of coal is transported away (3/7) for the first time, which is exactly 27 tons, and 25% of the whole is transported away for the second time. How many tons are transported for the second time?
一堆煤，第一次运走(3/7)，正好是27吨，第二次又运走全部的25%，第二次运走多少吨？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">27 / (3/7)</gadget>
<output>63</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">63 * (1/4)</gadget>
<output>63/4 = around 15.75</output>

<result>63/4 = around 15.75</result>