Solution ratio: ((0.2)/(x))=((0.9)/8).
解比例：((0.2)/(x))=((0.9)/8)．
<gadget id="calculator">0.9 / 8</gadget>
<output>0.1125</output>

<gadget id="calculator">0.2 / 0.1125</gadget>
<output>1.777778</output>

<result>1.777778</result>