Two passenger and freight trains start from A and B at the same time, drive toward each other, and meet at a distance of 30 km from the midpoint of the two places after 5 hours. It is known that the speed ratio of passenger and freight vehicles is 5:7, what is the distance between A and B?
客、货两车同时从甲、乙两地出发，相向而行，5小时后在距离两地中点30km处相遇．已知客货两车的速度比是5：7，求甲、乙之间距离多少？
<gadget id="calculator">5 + 7</gadget>
<output>12</output>

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

<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">(7/12) - (5/12)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">2 / (1/6)</gadget>
<output>12</output>

<gadget id="calculator">30 * 12</gadget>
<output>360</output>

<result>360</result>