A basket of apples weighs 28 kg. After selling half a basket of apples, the weight of the basket together is exactly 15 kilograms. How many kilograms does the basket weigh?
一筐苹果连筐重28千克．卖出半筐苹果后，连筐一起称刚好是15千克．请问筐重多少千克？
<gadget id="calculator">28 - 15</gadget>
<output>13</output>

<gadget id="calculator">15 - 13</gadget>
<output>2</output>

<result>2</result>