There are apples and pears in a basket, among which pears account for (9/20) of the total weight, and after 16 kg of apples are put in, pears only account for (1/4) of the total weight, how many kilograms are pears ?
一只筐中装有苹果和梨两种水果，其中梨占总重量的(9/20)，再放进16千克苹果后，梨就只占总重量的(1/4)，梨有多少千克？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">9 / 20</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">16 * (1/4) * (9/20)</gadget>
<output>9/5 = around 1.8</output>

<gadget id="calculator">(9/20) - (1/4)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(9/5) / (1/5)</gadget>
<output>9</output>

<result>9</result>