There are two boxes of candy, the first box weighs (9/10) Kg, if (1/5) Kg is taken out from the first box and put into the second box, then the weight of the two boxes of candy is equal. How much does the second box of candy weigh in Kg?
有两盒糖果，第一盒重(9/10)Kg，如果从第一盒中取出(1/5)Kg放入第二盒，这时两盒糖果的重量相等．第二盒糖果重多少Kg？
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(9/10) - (1/5) - (1/5)</gadget>
<output>1/2 = around 0.5</output>

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