Solution ratio. x: 50%=(3/5): 1.8.
解比例．x：50%=(3/5)：1.8．
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(1/2) * (3/5)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/10) / 1.8</gadget>
<output>0.166667</output>

<result>0.166667</result>