A factory needs to process 875 parts, 50 parts per hour, and the processing time is 3.5 hours. The rest process 56 pieces per hour, how many hours will it take to finish processing?
某工厂要加工875个零件，每小时加工50个，加工了3.5小时．剩下的每小时加工56个，还需几小时才能加工完？
<gadget id="calculator">50 * 3.5</gadget>
<output>175</output>

<gadget id="calculator">875 - 175</gadget>
<output>700</output>

<gadget id="calculator">700 / 56</gadget>
<output>25/2 = around 12.5</output>

<result>25/2 = around 12.5</result>