The two piles of goods A and B weigh the same. If the goods are transported from pile A each time (2/5), then after two shipments, the goods of pile B have just been shipped, and there are still 30 tons of goods left in pile A. Ask how many tons of goods A and B have in total?
甲、乙两堆货物一样重．如果每次从甲堆运走货物是每次从乙堆运走的(2/5)，那么运了两次以后，乙堆货物刚好运完，甲堆货物还剩下30吨．问原来甲、乙两堆货物共有多少吨？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">(1/2) * (2/5) * 2</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">30 / (3/5)</gadget>
<output>50</output>

<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<result>100</result>