A passenger car and a truck are traveling towards each other from A and B at the same time, and meet at a distance of 15 kilometers from the midpoint. It is known that the ratio of the speed of the passenger car to the speed of the truck is 7:5. How many kilometers is the distance between A and B?
客车和货车同时从甲乙两地相向而行，在离中点15千米处相遇，已知客车速度和货车速度的比是7：5，甲乙两地的路程是多少千米？
<gadget id="calculator">7 + 5</gadget>
<output>12</output>

<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(7/12) - (1/2)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">15 / (1/12)</gadget>
<output>180</output>

<result>180</result>