A supermarket buys a batch of fruits. The mass of apples is 30% of this batch of fruits, and the mass of pears is 25% of this batch of fruits. Apples are 30 kg more than pears. How many kg of this batch of fruits are there?
超市购进一批水果，苹果的质量是这批水果的30%，梨的质量是这批水果的25%，苹果比梨多30千克，这批水果共多少千克？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(3/10) - (1/4)</gadget>
<output>1/20 = around 0.05</output>

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

<result>600</result>