There is a batch of goods, 40% of which was transported on the first day, and the rest (5/8) was transported on the second day, and 15 tons more were transported on the first day than on the second day. How many tons did this batch of goods originally have?
有一批货物，第一天运走了40%，第二天运走了剩下的(5/8)，第一天比第二天多运走15吨．这批货物原有多少吨？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">(3/5) * (5/8)</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">(2/5) - (3/8)</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">15 / (1/40)</gadget>
<output>600</output>

<result>600</result>