There are 300 parts in one batch, which are processed on the first day (1/10) and processed on the second day (1/15). How many pieces were processed in two days?
一批零件共300个，第一天加工了(1/10)，第二天加工了(1/15)．两天共加工了多少个？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

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

<gadget id="calculator">(1/10) + (1/15)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">300 * (1/6)</gadget>
<output>50</output>

<result>50</result>