There is a box of apples. 20 kilograms were sold, which accounted for exactly (4/5) of the weight of the whole box. How many kilograms did the box of apples originally weigh?
有一箱苹果．卖去20千克，正好占全箱质量的(4/5)．这箱苹果原来有多少千克？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">20 / (4/5)</gadget>
<output>25</output>

<result>25</result>