The master and apprentice jointly process 680 parts, the master processes 48 per hour, and the apprentice processes 37 per hour. How many hours did they process this batch of parts?
师徒共同加工零件680个，师傅每小时加工48个，徒弟每小时加工37个．他们几小时加工完这批零件？
<gadget id="calculator">48 + 37</gadget>
<output>85</output>

<gadget id="calculator">680 / 85</gadget>
<output>8</output>

<result>8</result>