The number A is 25, (1/5) of the number A is equal to 40% of the number B, how much is B?
甲数是25，甲数的(1/5)等于乙数的40%，乙是多少？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">25 * (1/2)</gadget>
<output>25/2 = around 12.5</output>

<result>25/2 = around 12.5</result>