A batch of fruit is transported by car, and the tonnage transported on the first day accounts for 20% of the total weight. If another 15 tons are transported, half of this batch of fruits can be transported. How many tons is this batch of fruit?
用汽车运一批水果，第一天运的吨数占总重量的20%．如果再运15吨，就可以运完这批水果的一半．这批水果共有多少吨？
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">(1/2) - (1/5)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">15 / (3/10)</gadget>
<output>50</output>

<result>50</result>