Cars A and B start from places A and B at the same time and drive toward each other. They meet at a distance of 54 kilometers from place B. They each arrive at the starting place of the other car and immediately return to their original places. On the way, they are 42 kilometers away from place A. meet everywhere. Find the distance between the two meeting places.
甲、乙两车同时从A、B两地出发相向而行，在距B地54千米处相遇，他们各自到达对方车的出发地后立即返回原地，途中又在距A地42千米处相遇．求两次相遇地点的距离．
<gadget id="calculator">54 * 3</gadget>
<output>162</output>

<gadget id="calculator">162 - 42</gadget>
<output>120</output>

<gadget id="calculator">120 - 54 - 42</gadget>
<output>24</output>

<result>24</result>