There is a batch of goods in the market, 30% of the total quantity was transported on the first day, and 4 tons less than the total (1/4) was transported on the second day, leaving 31 tons at this time. How many tons is this shipment in total?
商场上有一批货，第一天运走了总数的30%，第二天运走的比总数的(1/4)少4吨，这时还剩下31吨．这批货物共有多少吨？
<gadget id="calculator">31 - 4</gadget>
<output>27</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

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

<gadget id="calculator">(3/10) + (1/4)</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">1 - (11/20)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">27 / (9/20)</gadget>
<output>60</output>

<result>60</result>