40% of how many kilometers is 5 kilometers.
多少千米的40%是5千米．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">5 / (2/5)</gadget>
<output>25/2 = around 12.5</output>

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