A basket of apples weighs 45.5 kg with the basket. After taking out half of the apples, the weight of the basket is 24.5 kg. How much does the basket weigh?
一筐苹果，连筐重45.5千克，取出一半后，连筐还重24.5千克，筐重多少千克？
<gadget id="calculator">45.5 - 24.5</gadget>
<output>21</output>

<gadget id="calculator">24.5 - 21</gadget>
<output>3.5</output>

<result>3.5</result>