A convoy transports a batch of goods. It transports 35% of the goods on the first day, 40% of the goods on the second day, and 1.8 tons more on the second day than on the first day. How many tons are there in total for this batch of goods? ?
一个车队运输一批货物，第一天运了这批货物的35%，第二天运了这批货物的40%，第二天比第一天多运了1.8吨，这批货物共有多少吨？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">(2/5) - (7/20)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1.8 / (1/20)</gadget>
<output>36</output>

<result>36</result>