When transporting a batch of fruit, 20% of it was shipped for the first time. If another 30 tons are shipped, then the already shipped accounted for 1/4 of the total fruit. How many tons are there in this batch of fruit?
运一批水果，第一次运了20%，如果再运30吨，那么这时已运的占全部水果的(1/4)，这批水果有多少吨？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) - (1/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">30 / (1/20)</gadget>
<output>600</output>

<result>600</result>