The speed ratio of the passenger car and the truck is 7:4. The two cars start from two places at the same time, go towards each other, and meet at a distance of 180 kilometers from the midpoint. How many kilometers has the passenger car traveled at this time?
客车与货车的速度比是7：4，两车同时从两地出发，相向而行，在离中点180千米处相遇，这时客车行了多少千米？
<gadget id="calculator">4 / 7</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">2 / (3/7)</gadget>
<output>14/3 = around 4.666667</output>

<gadget id="calculator">180 * (14/3)</gadget>
<output>840</output>

<result>840</result>