The number of passenger cars at a certain station is (5/7) the number of freight cars. After the passenger cars leave (1/5), the remaining passenger cars are 15 fewer than the freight cars. How many passenger cars are there in this station?
某车站客车的辆数是货车辆数的(5/7)，当客车开出(1/5)后，剩下的客车比货车少15辆，问该车站原有客车多少辆？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

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

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(5/7) * (4/5)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">1 - (4/7)</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">15 / (3/7)</gadget>
<output>35</output>

<gadget id="calculator">35 * (5/7)</gadget>
<output>25</output>

<result>25</result>