It takes 15 days for Master Wang to process this batch of parts alone, and 10 days for Master Li to process this batch of parts alone. They just completed 280 parts in 5 days of cooperation. How many parts are there in this batch?
王师傅单独加工这批零件要15天，李师傅单独加工这批零件要10天，他们合作5天正好完成了280个，这批零件共有多少个？
<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

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

<gadget id="calculator">(1/6) * 5</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">280 / (5/6)</gadget>
<output>336</output>

<result>336</result>