A basket of pears weighs 20 kilograms after 30% of the basket is sold, and 16 kilograms after 50 percent of the basket is sold. How many kilograms did the basket of pears originally have?
一筐梨，卖出30%后，连筐重20千克，卖出去50%后，连筐重16千克，这筐梨原有多少千克？
<gadget id="calculator">20 - 16</gadget>
<output>4</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(1/2) - (3/10)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">4 / (1/5)</gadget>
<output>20</output>

<result>20</result>