Xiao Ming spent 5.4 yuan to buy some eggs, and the vendor gave him two eggs for free. In this way, the average cost of each egg dropped by 3 cents. How many eggs did Xiao Ming buy?
小明花5.4元分钱买了一些鸡蛋，小贩又无偿送给他两个鸡蛋，这样一来，平均每个鸡蛋下降了3分钱，小明原来买了多少个鸡蛋．
<gadget id="calculator">20 - 2</gadget>
<output>18</output>

<result>18</result>