The ratio of A and B is 3:8, A's number is 4.5, find B's number.
甲、乙两数的比是3：8，甲数是4.5，求乙数．
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">4.5 / (3/8)</gadget>
<output>12</output>

<result>12</result>