A peddler bought a batch of fruit, and because the price was fair, he could sell 10 kilograms per day. After selling out, he found that the loss was large. The peddler bought the same amount of the same fruit for the second time, and lowered the price appropriately, so that he could sell it every day. 15 kg. According to calculations, due to weather and many other factors, the two losses are equivalent to: every 3 days after the fruit is sold, the remaining 5 kg will be lost by 1 kg. If the loss after the second 6 days is exactly equal to For the loss after the first 3 days, how many kilograms of fruit does the vendor purchase each time?
某商贩购进一批水果，由于价格公道，每天可以卖出10千克，卖完后发现，损耗较大，商贩第二次购进同样多的同种水果，适当压低价格，这样每天可卖出15千克，经测算，由于天气原因以及其它诸多因素，两次损耗均相当于：每卖出3天水果后，剩下5千克要损耗1千克，，若第二次6天后的损耗量恰好等于第一次3天后的损耗量，那么商贩每次购进水果是多少千克？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

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

<gadget id="calculator">15 * 3 * (4/5) * (1/5)</gadget>
<output>36/5 = around 7.2</output>

<gadget id="calculator">15 * 3 * (1/5)</gadget>
<output>9</output>

<gadget id="calculator">3 * 10 * (1/5)</gadget>
<output>6</output>

<gadget id="calculator">9 - 6</gadget>
<output>3</output>

<gadget id="calculator">(36/5) + 9 + 3</gadget>
<output>96/5 = around 19.2</output>

<gadget id="calculator">(4/5) * (1/5)</gadget>
<output>4/25 = around 0.16</output>

<gadget id="calculator">(1/5) - (1/5)</gadget>
<output>0</output>

<gadget id="calculator">(4/25) + 0</gadget>
<output>4/25 = around 0.16</output>

<gadget id="calculator">(96/5) / (4/25)</gadget>
<output>120</output>

<result>120</result>