It is known that A is inversely proportional to B, and the product of A and B is 1. If A=5, then B=how much.
已知A与B成反比例，且A与B的积是1．如果A=5，那么B=多少．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>