Master Wang processes 15 parts per hour, and Master Zhao processes 12 parts per hour. When two masters work together (2/3), how many parts are processed in total?
王师傅每时加工15个零件，赵师傅每时加工12个零件．两位师傅共同加工(2/3)时，共加工多少个零件？
<gadget id="calculator">15 + 12</gadget>
<output>27</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">27 * (2/3)</gadget>
<output>18</output>

<result>18</result>