The ratio of A to B is 2:5, the number of A is 10, what is the number of B.
甲与乙的比是2：5，甲数是10，乙数是多少．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">10 / (2/5)</gadget>
<output>25</output>

<result>25</result>