The number A is a, which is less than the number B (2/5), find the number B. The column type is: how much.
甲数是a，比乙数少(2/5)，求乙数．列式是：多少．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>