A basket of oranges weighs 25 kilograms, and after half of them are sold, the weight of the basket is 13.5 kilograms. How many kilograms does the basket weigh?
一筐橘子连筐重25千克，卖出一半后连筐重13.5千克，筐重多少千克？
<gadget id="calculator">25 - 13.5</gadget>
<output>11.5</output>

<gadget id="calculator">11.5 * 2</gadget>
<output>23</output>

<gadget id="calculator">25 - 23</gadget>
<output>2</output>

<result>2</result>