and B process a batch of parts. It takes 8 hours for A to process alone, and B can process (1/2) of this batch of parts in 5 hours alone, and A and B together process 207 parts in 4 hours. How many parts are there in this batch?
甲、乙二人加工一批零件．甲单独加工需8小时可以完成，乙单独加工5小时完成这批零件的(1/2)，甲乙合干4小时加工了207个．这批零件有多少个？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) / 5</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/8) + (1/10)</gadget>
<output>9/40 = around 0.225</output>

<gadget id="calculator">(9/40) * 4</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">207 / (9/10)</gadget>
<output>230</output>

<result>230</result>