(8/15)*(7/18)+(11/18)*(8/15).
(8/15)*(7/18)+(11/18)*(8/15)．
<gadget id="calculator">8 / 15</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">7 / 18</gadget>
<output>7/18 = around 0.388889</output>

<gadget id="calculator">(8/15) * (7/18)</gadget>
<output>28/135 = around 0.207407</output>

<gadget id="calculator">11 / 18</gadget>
<output>11/18 = around 0.611111</output>

<gadget id="calculator">(11/18) * (8/15)</gadget>
<output>44/135 = around 0.325926</output>

<gadget id="calculator">(28/135) + (44/135)</gadget>
<output>8/15 = around 0.533333</output>

<result>8/15 = around 0.533333</result>