The transport team wants to transport a batch of goods, and the ratio of the goods that have been transported to the rest is 1:4. If another 6 tons are transported away, the ratio of the transported to the remaining is 3:7. How many tons is this shipment?
运输队要运一批货物，已经运走的和剩下的比是1：4．如果再运走6吨，那么运走的和剩下的比为3：7．这批货物共多少吨？
<gadget id="calculator">3 + 7</gadget>
<output>10</output>

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

<gadget id="calculator">1 + 4</gadget>
<output>5</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(3/10) - (1/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">6 / (1/10)</gadget>
<output>60</output>

<result>60</result>