For a batch of goods, 27 tons were transported for the first time, and 30% of the total was transported for the second time. This is the ratio of the tonnage of the goods that have been shipped to the goods that have not been shipped is 3:1. How many tons are there in this batch of goods?
一批货物，第一次运走27吨，第二次运走总数的30%．这是已运走的货物与未运货物的吨数比是3：1，这批货物一共有多少吨？
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

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

<gadget id="calculator">(3/4) - (3/10)</gadget>
<output>9/20 = around 0.45</output>

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

<result>60</result>