The engineering team transported a batch of grain. 20% was transported on the first day, and 15 tons were transported less on the second day than on the first day. At this time, the remaining grain accounted for (5/8) of the total. How many tons is this batch of grain?
工程队运一批粮食．第一天运走20%，第二天比第一天少运15吨，这时剩下的粮食占总数的(5/8)．这批粮食共多少吨？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">1 - (5/8) - (1/5)</gadget>
<output>7/40 = around 0.175</output>

<gadget id="calculator">(1/5) - (7/40)</gadget>
<output>1/40 = around 0.025</output>

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

<result>600</result>