A basket of pears weighs 43.5 kg in total, and after taking out half of the pears, the total weight of the basket is 22.5 kg. How many kilograms of pears are there?
一筐梨，连筐共重43.5千克，取出一半梨后，连筐共重22.5千克．原来有梨多少千克．
<gadget id="calculator">43.5 - 22.5</gadget>
<output>21</output>

<gadget id="calculator">21 * 2</gadget>
<output>42</output>

<result>42</result>