The store shipped a batch of refrigerators and sold 18 units. The ratio of the number of units sold to the number of remaining units is 3:2. How many units are left? (Solution by proportional method)
商店运来一批电冰箱，卖了18台，卖出的台数与剩下的台数比是3：2，求剩下电冰箱多少台？(用比例方法解)
<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">18 / (3/2)</gadget>
<output>12</output>

<result>12</result>