Two cars A and B are driving towards each other from A and B at the same time. After 4 hours, the two cars meet. After meeting, A travels for another 3 hours to reach B. At this time, B has to travel 15 kilometers to reach A. What is the distance between A and B in kilometers?
甲乙两辆汽车同时从A、B两地相对而行，经过4小时两车相遇，相遇后甲车又行了3小时到达B地，这时乙车还要行15千米才能到达A地，A、B两地相距多少千米．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) * 3</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">15 / (1/4)</gadget>
<output>60</output>

<result>60</result>