The ratio of A and B is 2:5, A's number is 40, what is B's number?
甲、乙两数的比是2：5，甲数是40，乙数是多少．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">40 / (2/5)</gadget>
<output>100</output>

<result>100</result>