There is a box of fruit with a water content of 90%. After a period of time, the water content drops to 80%. What is the weight of this box of fruit now?
有一箱含水量为90%的水果，经过一段时间后，含水量降为80%，现在这箱水果的重量是原来的多少．
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 - (9/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

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

<gadget id="calculator">(1/10) / (1/5)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>