(1-((1/12)+(1/15))*2)/((3/10)/(9/20)).
(1-((1/12)+(1/15))*2)/((3/10)/(9/20))．
<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/12) + (1/15)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(3/20) * 2</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">9 / 20</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">(3/10) / (9/20)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(7/10) / (2/3)</gadget>
<output>21/20 = around 1.05</output>

<result>21/20 = around 1.05</result>