There is a batch of goods in the market, 1/3 of the total amount was shipped out on the first day, and 40% of the total amount was shipped out on the second day. At this time, there are still 20 tons left. How many tons are there in total in this batch?
商场上有一批货，第一天运走了总数的(1/3)，第二天运走了总数的40%，这时还剩20吨，这批货物共有多少吨？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/3) - (2/5)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">20 / (4/15)</gadget>
<output>75</output>

<result>75</result>