The ratio of the number of watermelons to the number of white melons in the fruit shop is 7:5. If you sell 40 white melons and 50 watermelons every day, after a few days, the white melons will be sold out and there will be 36 watermelons left. How many watermelons are there in the fruit shop?
水果店里西瓜个数与白兰瓜个数的比为7：5．如果每天卖白兰瓜40个，西瓜50个，若干天后，白兰瓜正好卖完，西瓜还剩36个．水果店里原有西瓜多少个？
<gadget id="calculator">7 / 5</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">36 / 50</gadget>
<output>18/25 = around 0.72</output>

<gadget id="calculator">(7/5) * (18/25) * 40</gadget>
<output>1_008/25 = around 40.32</output>

<gadget id="calculator">1 / 50</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">(7/5) * (1/50) * 40</gadget>
<output>28/25 = around 1.12</output>

<gadget id="calculator">(28/25) - 1</gadget>
<output>3/25 = around 0.12</output>

<gadget id="calculator">(1_008/25) / (3/25)</gadget>
<output>336</output>

<result>336</result>