The postman Xiao Li delivered the letter from A to B, and returned immediately after delivery. It took 2.7 hours. Xiao Li went at a speed of 12 kilometers per hour and returned at a speed of 15 kilometers per hour. Find the distance between the two places distance.
邮递员小李从A地到B地送信，送到后立即返回，共用了2.7小时，小李去时的速度是每小时12千米，回来时的速度是每小时15千米，求两地间的距离．
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">2.7 * (5/9)</gadget>
<output>1.5</output>

<gadget id="calculator">12 * 1.5</gadget>
<output>18</output>

<result>18</result>