Cars A and B start from opposite sides of cities A and B at the same time. Car A's speed is 90km/hour, and car B's speed is 60km/hour. After meeting on the way, they continue to move forward and reach their destinations. They each rest for 1 hour, and then return along the original road. When the two cars meet again, they are exactly 25km away from city A. How many kilometers are there between the two cities of AB?
甲乙两车同时从A、B两城相向出发，甲车速度为90km/时，乙车速度为60km/时，途中相遇后继续前行到达目的地后各自休息1小时，然后沿原路返回．当两车再次相遇时，离A城正好25km，AB两城相距多少km？
<gadget id="calculator">25 / 60</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">25 / 90</gadget>
<output>5/18 = around 0.277778</output>

<gadget id="calculator">(5/12) + (5/18)</gadget>
<output>25/36 = around 0.694444</output>

<gadget id="calculator">2 / 90</gadget>
<output>1/45 = around 0.022222</output>

<gadget id="calculator">1 / 60</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">(1/45) - (1/60)</gadget>
<output>1/180 = around 0.005556</output>

<gadget id="calculator">(25/36) / (1/180)</gadget>
<output>125</output>

<result>125</result>